{
  "name": "Esperanto in numbers",
  "description": "Figures about Esperanto: speakers, organised movement, Esperanto online, World Esperanto Congresses, the language itself and its organisations. Each figure has a date, a definition, a source and the day it was last checked.",
  "url": "https://esperantopedia.org/about/esperanto-in-numbers/",
  "version": "2026-11-05",
  "dateModified": "2026-11-05",
  "creator": {
    "name": "Esperantopedia",
    "url": "https://esperantopedia.org/"
  },
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
  "licenseNote": "The compilation (selection, definitions and our own counts) is by Esperantopedia, licensed CC BY-SA 4.0. The figures come from the sources named in each row; when you use a single figure, cite its source too.",
  "citation": "Esperantopedia (2026). Esperanto in numbers. https://esperantopedia.org/about/esperanto-in-numbers/",
  "distribution": {
    "csv": "https://esperantopedia.org/downloads/esperanto-in-numbers.csv",
    "json": "https://esperantopedia.org/downloads/esperanto-in-numbers.json"
  },
  "fields": {
    "id": "Stable identifier of the row",
    "metric": "What is counted",
    "value": "The figure (empty when only a range is known)",
    "value_low": "Lower end of a range or margin",
    "value_high": "Upper end of a range or margin",
    "unit": "Unit of the figure",
    "date": "Year, day or ISO 8601 interval the figure refers to (empty: undated source)",
    "definition": "Scope and definition of the figure",
    "method": "\"reported\": as published by the source; \"our count\", \"our calculation\", \"our sum\", \"our summary\": calculated by Esperantopedia from the published data",
    "live": "true for live counts that change daily",
    "sources": "Sources of the figure (title and URL)",
    "checked": "Day the figure was last compared with its source"
  },
  "metrics": [
    {
      "id": "speakers_estimates_range",
      "section": "speakers",
      "metric": "Esperanto speakers, range of published estimates",
      "value": null,
      "value_low": 60000,
      "value_high": 2000000,
      "unit": "people",
      "date": "1958/2017",
      "definition": "Range given on this page, rounded from the lowest and highest estimates in this section: about 63,000 people who would say yes in a census (Nielsen 2017) and about 2 million (Culbert, rounded in 1988; Wandel 2015: 1.92 million); the estimates differ mainly in how they define a speaker",
      "method": "our summary",
      "sources": [
        {
          "title": "Libera Folio, Nova takso: 60.000 parolas Esperanton (13 Feb 2017)",
          "url": "https://www.liberafolio.org/2017/02/13/nova-takso-60-000-parolas-esperanton/"
        },
        {
          "title": "Wandel, How many people speak Esperanto? (2015)",
          "url": "https://doi.org/10.7906/indecs.13.2.9"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "native_speakers_lindstedt",
      "section": "speakers",
      "metric": "Native speakers of Esperanto (Lindstedt)",
      "value": 1000,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "2006",
      "definition": "People who learned Esperanto from birth, estimate by Jouko Lindstedt (1996, 2006)",
      "method": "reported",
      "sources": [
        {
          "title": "Lindstedt, Native Esperanto as a test case for natural language (2006)",
          "url": "https://journal.fi/finjol/article/view/153130/98645"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "native_speaker_children_corsetti",
      "section": "speakers",
      "metric": "Children raised with Esperanto",
      "value": 2000,
      "value_low": null,
      "value_high": null,
      "unit": "children",
      "date": "2004",
      "definition": "Children growing up with Esperanto in about 1,000 families (Corsetti, Pinto & Tolomeo)",
      "method": "reported",
      "sources": [
        {
          "title": "Corsetti, Pinto & Tolomeo, Regularizing the regular (2004)",
          "url": "https://doi.org/10.1075/lplp.28.3.04cor"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "native_speakers_ethnologue",
      "section": "speakers",
      "metric": "Native speakers of Esperanto (Ethnologue)",
      "value": 1000,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "2022",
      "definition": "Native speakers listed by Ethnologue, 25th edition",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Esperanto (infobox, citing Ethnologue, 25th ed., 2022)",
          "url": "https://en.wikipedia.org/wiki/Esperanto"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "fluent_speakers_lindstedt",
      "section": "speakers",
      "metric": "Fluent speakers of Esperanto (Lindstedt's scale)",
      "value": 10000,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "1996",
      "definition": "Fluent speakers in Jouko Lindstedt's scale of 1,000 native, 10,000 fluent, 100,000 active and 1 million passive speakers",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Esperanto: Number of speakers",
          "url": "https://en.wikipedia.org/wiki/Esperanto#Number_of_speakers"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "organised_speakers_2003",
      "section": "speakers",
      "metric": "Members of Esperanto organisations",
      "value": 20000,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "2003",
      "definition": "Members of Esperanto organisations; Ziko van Dijk doubted that fifty times as many unorganised speakers exist",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Esperanto: Number of speakers",
          "url": "https://en.wikipedia.org/wiki/Esperanto#Number_of_speakers"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "census_speakers_nielsen",
      "section": "speakers",
      "metric": "People who would say yes in a census (Nielsen)",
      "value": 63000,
      "value_low": 30000,
      "value_high": 180000,
      "unit": "people",
      "date": "2017",
      "definition": "Estimate by Svend Vendelbo Nielsen from census, membership and website data, with its margin",
      "method": "reported",
      "sources": [
        {
          "title": "Libera Folio, Nova takso: 60.000 parolas Esperanton (13 Feb 2017)",
          "url": "https://www.liberafolio.org/2017/02/13/nova-takso-60-000-parolas-esperanton/"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "speakers_lindstedt",
      "section": "speakers",
      "metric": "People who can really speak Esperanto (Lindstedt)",
      "value": 100000,
      "value_low": 30000,
      "value_high": 300000,
      "unit": "people",
      "date": "2006",
      "definition": "Estimate by Jouko Lindstedt, with its range",
      "method": "reported",
      "sources": [
        {
          "title": "Lindstedt, Native Esperanto as a test case for natural language (2006)",
          "url": "https://journal.fi/finjol/article/view/153130/98645"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "speakers_culbert",
      "section": "speakers",
      "metric": "People with professional proficiency (Culbert)",
      "value": null,
      "value_low": 1000000,
      "value_high": 2000000,
      "unit": "people",
      "date": "1958/1989",
      "definition": "Sidney Culbert's estimate from sample surveys; rounded to 2 million from 1988",
      "method": "reported",
      "sources": [
        {
          "title": "Culbert, letter on his methods (24 Oct 1989, archived)",
          "url": "https://web.archive.org/web/20101120200544/http://www.panix.com/~dwolff/docs/culbert-methods.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "speakers_wandel",
      "section": "speakers",
      "metric": "Esperanto users among internet users (Wandel)",
      "value": 1920000,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "2015",
      "definition": "Amri Wandel's estimate, scaled up from 320,000 Facebook users at the end of 2014",
      "method": "reported",
      "sources": [
        {
          "title": "Wandel, How many people speak Esperanto? (2015)",
          "url": "https://doi.org/10.7906/indecs.13.2.9"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_individual_members_2023",
      "section": "movement",
      "metric": "UEA individual members",
      "value": 4700,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2023",
      "definition": "Individual members of the Universal Esperanto Association (UEA), in 130 countries and territories",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_countries_2023",
      "section": "movement",
      "metric": "Countries and territories with UEA individual members",
      "value": 130,
      "value_low": null,
      "value_high": null,
      "unit": "countries and territories",
      "date": "2023",
      "definition": "Countries and territories where UEA had individual members",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_individual_members_2022",
      "section": "movement",
      "metric": "UEA individual members",
      "value": 4552,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2022",
      "definition": "Individual members of UEA",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_individual_members_2010",
      "section": "movement",
      "metric": "UEA individual members",
      "value": 5288,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2010",
      "definition": "Individual members of UEA (in 120 countries, according to UEA)",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Ĝeneralaj klarigoj pri la strukturo",
          "url": "https://uea.org/asocio/ghenerale"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "uea_individual_members_2015",
      "section": "movement",
      "metric": "UEA individual members",
      "value": 5501,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2015",
      "definition": "Individual members of UEA",
      "method": "reported",
      "sources": [
        {
          "title": "Libera Folio, Kie estas la Duolinganoj? (31 Mar 2020)",
          "url": "https://www.liberafolio.org/2020/03/31/kie-estas-la-duolinganoj/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "uea_individual_members_2019",
      "section": "movement",
      "metric": "UEA individual members",
      "value": 4162,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2019",
      "definition": "Individual members of UEA",
      "method": "reported",
      "sources": [
        {
          "title": "Libera Folio, Kie estas la Duolinganoj? (31 Mar 2020)",
          "url": "https://www.liberafolio.org/2020/03/31/kie-estas-la-duolinganoj/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "uea_individual_and_affiliated_members_2023",
      "section": "movement",
      "metric": "UEA individual plus affiliated members",
      "value": 12829,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2023",
      "definition": "Individual members plus members of national associations affiliated to UEA",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_members_france_2023",
      "section": "movement",
      "metric": "UEA individual members in France",
      "value": 401,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2023",
      "definition": "Largest national group of UEA individual members",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_members_germany_2023",
      "section": "movement",
      "metric": "UEA individual members in Germany",
      "value": 394,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2023",
      "definition": "Second largest national group of UEA individual members",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_members_brazil_2023",
      "section": "movement",
      "metric": "UEA individual members in Brazil",
      "value": 279,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2023",
      "definition": "Third largest national group of UEA individual members",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_members_usa_2023",
      "section": "movement",
      "metric": "UEA individual members in the United States",
      "value": 248,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2023",
      "definition": "Fourth largest national group of UEA individual members",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_members_japan_2023",
      "section": "movement",
      "metric": "UEA individual members in Japan",
      "value": 209,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2023",
      "definition": "Fifth largest national group of UEA individual members",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "uea_national_associations",
      "section": "movement",
      "metric": "National associations affiliated to UEA",
      "value": 70,
      "value_low": null,
      "value_high": null,
      "unit": "associations",
      "date": "",
      "definition": "Figure on an undated UEA page; Vikipedio gives about 60",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Ĝeneralaj klarigoj pri la strukturo",
          "url": "https://uea.org/asocio/ghenerale"
        },
        {
          "title": "Vikipedio, Membronombroj de UEA",
          "url": "https://eo.wikipedia.org/wiki/Membronombroj_de_UEA"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "hungary_census_1990",
      "section": "movement",
      "metric": "People in Hungary who know Esperanto (census)",
      "value": 2083,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "1990",
      "definition": "Hungarian census answers",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Languages of the European Union",
          "url": "https://en.wikipedia.org/wiki/Languages_of_the_European_Union"
        },
        {
          "title": "Libera Folio, Nova takso: 60.000 parolas Esperanton (13 Feb 2017)",
          "url": "https://www.liberafolio.org/2017/02/13/nova-takso-60-000-parolas-esperanton/"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "hungary_census_2001",
      "section": "movement",
      "metric": "People in Hungary who know Esperanto (census)",
      "value": 4575,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "2001",
      "definition": "Hungarian census answers",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Languages of the European Union",
          "url": "https://en.wikipedia.org/wiki/Languages_of_the_European_Union"
        },
        {
          "title": "Libera Folio, Nova takso: 60.000 parolas Esperanton (13 Feb 2017)",
          "url": "https://www.liberafolio.org/2017/02/13/nova-takso-60-000-parolas-esperanton/"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "hungary_census_2011",
      "section": "movement",
      "metric": "People in Hungary who know Esperanto (census)",
      "value": 8397,
      "value_low": null,
      "value_high": null,
      "unit": "people",
      "date": "2011",
      "definition": "Hungarian census answers; the rise reflects state language exams that accepted Esperanto",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Languages of the European Union",
          "url": "https://en.wikipedia.org/wiki/Languages_of_the_European_Union"
        },
        {
          "title": "Libera Folio, Nova takso: 60.000 parolas Esperanton (13 Feb 2017)",
          "url": "https://www.liberafolio.org/2017/02/13/nova-takso-60-000-parolas-esperanton/"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "pasporta_servo_hosts",
      "section": "movement",
      "metric": "Pasporta Servo hosts",
      "value": 2400,
      "value_low": null,
      "value_high": null,
      "unit": "hosts",
      "date": "2026-11-05",
      "definition": "Registered hosts of the Esperanto hospitality network run by TEJO; the site says more than 2,400",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Pasporta Servo, home page",
          "url": "https://www.pasportaservo.org/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "pasporta_servo_countries",
      "section": "movement",
      "metric": "Countries with Pasporta Servo hosts",
      "value": 121,
      "value_low": null,
      "value_high": null,
      "unit": "countries",
      "date": "2026-11-05",
      "definition": "Countries where Pasporta Servo hosts live",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Pasporta Servo, home page",
          "url": "https://www.pasportaservo.org/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "pasporta_servo_cities",
      "section": "movement",
      "metric": "Cities with Pasporta Servo hosts",
      "value": 1801,
      "value_low": null,
      "value_high": null,
      "unit": "cities",
      "date": "2026-11-05",
      "definition": "Cities where Pasporta Servo hosts offer a place to stay",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Pasporta Servo, home page",
          "url": "https://www.pasportaservo.org/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "eo_wikipedia_articles",
      "section": "online",
      "metric": "Articles in the Esperanto Wikipedia (Vikipedio)",
      "value": 390439,
      "value_low": null,
      "value_high": null,
      "unit": "articles",
      "date": "2026-11-05",
      "definition": "Content pages counted by MediaWiki (Special:Statistics and its API); the Wikimedia list of Wikipedias gave 390,438 the same day",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Vikipedio, Special:Statistics",
          "url": "https://eo.wikipedia.org/wiki/Special:Statistics"
        },
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "eo_wikipedia_rank",
      "section": "online",
      "metric": "Rank of the Esperanto Wikipedia by number of articles",
      "value": 38,
      "value_low": null,
      "value_high": null,
      "unit": "rank",
      "date": "2026-11-05",
      "definition": "Place among the active Wikipedia language editions, by number of articles; the largest Wikipedia in a constructed language",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "wikipedia_active_editions",
      "section": "online",
      "metric": "Active Wikipedia language editions",
      "value": 348,
      "value_low": null,
      "value_high": null,
      "unit": "language editions",
      "date": "2026-11-05",
      "definition": "Active editions of Wikipedia, not counting 16 closed ones",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        },
        {
          "title": "Wikipedia, List of Wikipedias",
          "url": "https://en.wikipedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "eo_wikipedia_active_users",
      "section": "online",
      "metric": "Active registered users of the Esperanto Wikipedia",
      "value": 407,
      "value_low": null,
      "value_high": null,
      "unit": "users",
      "date": "2026-11-05",
      "definition": "Registered users who performed an action in the last 30 days",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Vikipedio, Special:Statistics",
          "url": "https://eo.wikipedia.org/wiki/Special:Statistics"
        },
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "io_wikipedia_articles",
      "section": "online",
      "metric": "Articles in the Ido Wikipedia",
      "value": 65274,
      "value_low": null,
      "value_high": null,
      "unit": "articles",
      "date": "2026-11-05",
      "definition": "Content pages counted by MediaWiki, for comparison with other constructed languages",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Ido Wikipedia, Special:Statistics",
          "url": "https://io.wikipedia.org/wiki/Special:Statistics"
        },
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "vo_wikipedia_articles",
      "section": "online",
      "metric": "Articles in the Volapük Wikipedia",
      "value": 57577,
      "value_low": null,
      "value_high": null,
      "unit": "articles",
      "date": "2026-11-05",
      "definition": "Content pages counted by MediaWiki, for comparison with other constructed languages",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Volapük Wikipedia, Special:Statistics",
          "url": "https://vo.wikipedia.org/wiki/Special:Statistics"
        },
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "ia_wikipedia_articles",
      "section": "online",
      "metric": "Articles in the Interlingua Wikipedia",
      "value": 30453,
      "value_low": null,
      "value_high": null,
      "unit": "articles",
      "date": "2026-11-05",
      "definition": "Content pages counted by MediaWiki, for comparison with other constructed languages",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Interlingua Wikipedia, Special:Statistics",
          "url": "https://ia.wikipedia.org/wiki/Special:Statistics"
        },
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "ie_wikipedia_articles",
      "section": "online",
      "metric": "Articles in the Interlingue Wikipedia",
      "value": 13834,
      "value_low": null,
      "value_high": null,
      "unit": "articles",
      "date": "2026-11-05",
      "definition": "Content pages counted by MediaWiki, for comparison with other constructed languages",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Interlingue Wikipedia, Special:Statistics",
          "url": "https://ie.wikipedia.org/wiki/Special:Statistics"
        },
        {
          "title": "Wikimedia Meta-Wiki, List of Wikipedias",
          "url": "https://meta.wikimedia.org/wiki/List_of_Wikipedias"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "eo_wikipedia_monthly_pageviews",
      "section": "online",
      "metric": "Human page views of the Esperanto Wikipedia per month",
      "value": 2038906,
      "value_low": null,
      "value_high": null,
      "unit": "page views per month",
      "date": "2025-11/2026-10",
      "definition": "Median of 12 monthly totals of page views by users (not bots or spiders); the median leaves out a spike of 14.6 million in November 2025",
      "method": "our calculation",
      "live": true,
      "sources": [
        {
          "title": "Wikimedia pageviews API, eo.wikipedia, monthly, user agents",
          "url": "https://wikimedia.org/api/rest_v1/metrics/pageviews/aggregate/eo.wikipedia/all-access/user/monthly/2025110100/2026103100"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_sentences_eo",
      "section": "online",
      "metric": "Esperanto sentences on Tatoeba",
      "value": 824751,
      "value_low": null,
      "value_high": null,
      "unit": "sentences",
      "date": "2026-11-05",
      "definition": "Sentences in Esperanto in the Tatoeba collection, as listed on its statistics page (the Tatoeba API returned 824,339 the same day)",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Number of sentences per language",
          "url": "https://tatoeba.org/en/stats/sentences_by_language"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_sentences_eo_rank",
      "section": "online",
      "metric": "Rank of Esperanto on Tatoeba by number of sentences",
      "value": 4,
      "value_low": null,
      "value_high": null,
      "unit": "rank",
      "date": "2026-11-05",
      "definition": "Place among 432 languages, after English, Russian and Italian",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Number of sentences per language",
          "url": "https://tatoeba.org/en/stats/sentences_by_language"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_languages",
      "section": "online",
      "metric": "Languages with sentences on Tatoeba",
      "value": 432,
      "value_low": null,
      "value_high": null,
      "unit": "languages",
      "date": "2026-11-05",
      "definition": "Languages listed on the Tatoeba statistics page",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Number of sentences per language",
          "url": "https://tatoeba.org/en/stats/sentences_by_language"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_sentences_en",
      "section": "online",
      "metric": "English sentences on Tatoeba",
      "value": 2048834,
      "value_low": null,
      "value_high": null,
      "unit": "sentences",
      "date": "2026-11-05",
      "definition": "For comparison: the largest language on Tatoeba",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Number of sentences per language",
          "url": "https://tatoeba.org/en/stats/sentences_by_language"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_sentences_ru",
      "section": "online",
      "metric": "Russian sentences on Tatoeba",
      "value": 1235449,
      "value_low": null,
      "value_high": null,
      "unit": "sentences",
      "date": "2026-11-05",
      "definition": "For comparison: second on Tatoeba",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Number of sentences per language",
          "url": "https://tatoeba.org/en/stats/sentences_by_language"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_sentences_it",
      "section": "online",
      "metric": "Italian sentences on Tatoeba",
      "value": 991346,
      "value_low": null,
      "value_high": null,
      "unit": "sentences",
      "date": "2026-11-05",
      "definition": "For comparison: third on Tatoeba",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Number of sentences per language",
          "url": "https://tatoeba.org/en/stats/sentences_by_language"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_audio_eo",
      "section": "online",
      "metric": "Esperanto audio recordings on Tatoeba",
      "value": 82553,
      "value_low": null,
      "value_high": null,
      "unit": "recordings",
      "date": "2026-11-05",
      "definition": "Sentences with audio in Esperanto, as listed on Tatoeba's audio page (the Tatoeba API listed 82,555 recordings the same day)",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Sentences with audio",
          "url": "https://tatoeba.org/en/audio/index"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_audio_eo_rank",
      "section": "online",
      "metric": "Rank of Esperanto on Tatoeba by audio recordings",
      "value": 3,
      "value_low": null,
      "value_high": null,
      "unit": "rank",
      "date": "2026-11-05",
      "definition": "Place after English and Spanish",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Sentences with audio",
          "url": "https://tatoeba.org/en/audio/index"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_audio_en",
      "section": "online",
      "metric": "English audio recordings on Tatoeba",
      "value": 850274,
      "value_low": null,
      "value_high": null,
      "unit": "recordings",
      "date": "2026-11-05",
      "definition": "For comparison: first on Tatoeba",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Sentences with audio",
          "url": "https://tatoeba.org/en/audio/index"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "tatoeba_audio_es",
      "section": "online",
      "metric": "Spanish audio recordings on Tatoeba",
      "value": 119428,
      "value_low": null,
      "value_high": null,
      "unit": "recordings",
      "date": "2026-11-05",
      "definition": "For comparison: second on Tatoeba",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Tatoeba, Sentences with audio",
          "url": "https://tatoeba.org/en/audio/index"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "lernu_registered_users_2011",
      "section": "online",
      "metric": "Registered users of lernu.net",
      "value": 100000,
      "value_low": null,
      "value_high": null,
      "unit": "users",
      "date": "2011-05-29",
      "definition": "Registered users on the day the site reached 100,000; lernu.net was launched on 21 December 2002",
      "method": "reported",
      "sources": [
        {
          "title": "Vikipedio, Lernu!",
          "url": "https://eo.wikipedia.org/wiki/Lernu!"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "lernu_interface_languages",
      "section": "online",
      "metric": "Interface languages of lernu.net",
      "value": 40,
      "value_low": null,
      "value_high": null,
      "unit": "languages",
      "date": "2026-11-05",
      "definition": "Languages of the lernu.net interface menu",
      "method": "our count",
      "live": true,
      "sources": [
        {
          "title": "lernu.net",
          "url": "https://lernu.net/en"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "duolingo_learners_2020",
      "section": "online",
      "metric": "People who started Duolingo's Esperanto courses",
      "value": 2800000,
      "value_low": null,
      "value_high": null,
      "unit": "learners",
      "date": "2020-03",
      "definition": "Course starters since 2015, according to Duolingo; learners, not speakers",
      "method": "reported",
      "sources": [
        {
          "title": "Libera Folio, Kie estas la Duolinganoj? (31 Mar 2020)",
          "url": "https://www.liberafolio.org/2020/03/31/kie-estas-la-duolinganoj/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "duolingo_learners_via_english_2020",
      "section": "online",
      "metric": "People who started Duolingo's Esperanto course for English speakers",
      "value": 1600000,
      "value_low": null,
      "value_high": null,
      "unit": "learners",
      "date": "2020-03",
      "definition": "Course starters, according to Duolingo",
      "method": "reported",
      "sources": [
        {
          "title": "Libera Folio, Kie estas la Duolinganoj? (31 Mar 2020)",
          "url": "https://www.liberafolio.org/2020/03/31/kie-estas-la-duolinganoj/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "duolingo_learners_via_spanish_2020",
      "section": "online",
      "metric": "People who started Duolingo's Esperanto course for Spanish speakers",
      "value": 871000,
      "value_low": null,
      "value_high": null,
      "unit": "learners",
      "date": "2020-03",
      "definition": "Course starters, according to Duolingo",
      "method": "reported",
      "sources": [
        {
          "title": "Libera Folio, Kie estas la Duolinganoj? (31 Mar 2020)",
          "url": "https://www.liberafolio.org/2020/03/31/kie-estas-la-duolinganoj/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "duolingo_learners_via_portuguese_2020",
      "section": "online",
      "metric": "People who started Duolingo's Esperanto course for Portuguese speakers",
      "value": 376000,
      "value_low": null,
      "value_high": null,
      "unit": "learners",
      "date": "2020-03",
      "definition": "Course starters, according to Duolingo",
      "method": "reported",
      "sources": [
        {
          "title": "Libera Folio, Kie estas la Duolinganoj? (31 Mar 2020)",
          "url": "https://www.liberafolio.org/2020/03/31/kie-estas-la-duolinganoj/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "duolingo_en_course_units",
      "section": "online",
      "metric": "Units in Duolingo's Esperanto course for English speakers",
      "value": 69,
      "value_low": null,
      "value_high": null,
      "unit": "units",
      "date": "2026-11-05",
      "definition": "Course version of July 2025, level A1; from an unofficial tracker",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Duolingo Data (unofficial tracker)",
          "url": "https://duolingodata.com/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "duolingo_en_course_lessons",
      "section": "online",
      "metric": "Lessons in Duolingo's Esperanto course for English speakers",
      "value": 1318,
      "value_low": null,
      "value_high": null,
      "unit": "lessons",
      "date": "2026-11-05",
      "definition": "Course version of July 2025, level A1; from an unofficial tracker",
      "method": "reported",
      "live": true,
      "sources": [
        {
          "title": "Duolingo Data (unofficial tracker)",
          "url": "https://duolingodata.com/"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "google_translate_language_number",
      "section": "online",
      "metric": "Esperanto's place in the order of Google Translate languages",
      "value": 64,
      "value_low": null,
      "value_high": null,
      "unit": "ordinal",
      "date": "2012-02-22",
      "definition": "Google Translate added Esperanto as its 64th language; Yandex Translate followed on 25 July 2016",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Esperanto",
          "url": "https://en.wikipedia.org/wiki/Esperanto"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congresses_numbered",
      "section": "congresses",
      "metric": "World Esperanto Congresses numbered",
      "value": 111,
      "value_low": null,
      "value_high": null,
      "unit": "congresses",
      "date": "1905/2026",
      "definition": "Congresses numbered from Boulogne-sur-Mer 1905 to Graz 2026 (the 111th)",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congresses_held",
      "section": "congresses",
      "metric": "World Esperanto Congresses held",
      "value": 108,
      "value_low": null,
      "value_high": null,
      "unit": "congresses",
      "date": "1905/2026",
      "definition": "Numbered congresses that took place",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congresses_cancelled",
      "section": "congresses",
      "metric": "World Esperanto Congresses cancelled",
      "value": 3,
      "value_low": null,
      "value_high": null,
      "unit": "congresses",
      "date": "1914/2021",
      "definition": "Paris 1914 (war), Montreal 2020 and Belfast 2021 (COVID-19); Montreal was held in 2022 instead",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_1914_registered",
      "section": "congresses",
      "metric": "People registered for the cancelled Paris congress",
      "value": 3739,
      "value_low": null,
      "value_high": null,
      "unit": "registrants",
      "date": "1914",
      "definition": "Registrations for the 10th congress, cancelled because of the war",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "virtual_congress_2020_registrants",
      "section": "congresses",
      "metric": "Registrants of the Virtual World Congress",
      "value": 2000,
      "value_low": null,
      "value_high": null,
      "unit": "registrants",
      "date": "2020",
      "definition": "About 2,000 registrants of the online congress held instead of Montreal 2020",
      "method": "reported",
      "sources": [
        {
          "title": "Virtuala Kongreso 2020, registrants",
          "url": "https://vk.esperanto.net/2020/aligxintoj/"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "virtual_congress_2021_registrants",
      "section": "congresses",
      "metric": "Registrants of the Virtual World Congress",
      "value": 1850,
      "value_low": null,
      "value_high": null,
      "unit": "registrants",
      "date": "2021",
      "definition": "About 1,850 registrants of the online congress held instead of Belfast 2021",
      "method": "reported",
      "sources": [
        {
          "title": "Virtuala Kongreso 2021, registrants",
          "url": "https://vk.esperanto.net/2021/aligxintoj/"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_1905_participants",
      "section": "congresses",
      "metric": "Participants of the first World Congress (Boulogne-sur-Mer)",
      "value": 688,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "1905",
      "definition": "First World Esperanto Congress, August 1905",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_1987_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in Warsaw",
      "value": 5946,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "1987",
      "definition": "The largest World Esperanto Congress",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_1923_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in Nuremberg",
      "value": 4963,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "1923",
      "definition": "The second largest World Esperanto Congress",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_1915_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in San Francisco",
      "value": 163,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "1915",
      "definition": "The smallest World Esperanto Congress",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congresses_3000_plus",
      "section": "congresses",
      "metric": "World Congresses with 3,000 participants or more",
      "value": 10,
      "value_low": null,
      "value_high": null,
      "unit": "congresses",
      "date": "1923/1998",
      "definition": "Congresses with at least 3,000 participants; the last was Montpellier 1998",
      "method": "our count",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_1998_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in Montpellier",
      "value": 3133,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "1998",
      "definition": "The last congress with 3,000 participants or more",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_median_participants",
      "section": "congresses",
      "metric": "Median participants of a World Congress",
      "value": 1634,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "1905/2026",
      "definition": "Median of the 108 congresses held",
      "method": "our calculation",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_mean_participants",
      "section": "congresses",
      "metric": "Mean participants of a World Congress",
      "value": 1774,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "1905/2026",
      "definition": "Mean of the 108 congresses held",
      "method": "our calculation",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_mean_participants_since_2016",
      "section": "congresses",
      "metric": "Mean participants of a World Congress since 2016",
      "value": 1135,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "2016/2026",
      "definition": "Mean of the 9 congresses held since 2016",
      "method": "our calculation",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_2023_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in Turin (UEA list)",
      "value": 1318,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "2023",
      "definition": "Figure in UEA's list of congresses; UEA's annual report counts 1,323 registrants from 70 countries",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_2023_registrants_report",
      "section": "congresses",
      "metric": "Registrants of the World Congress in Turin (UEA annual report)",
      "value": 1323,
      "value_low": null,
      "value_high": null,
      "unit": "registrants",
      "date": "2023",
      "definition": "Registrants from 70 countries, according to UEA's annual report for 2023",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, Estrara Raporto 2023",
          "url": "https://esperantohea.hu/wp-content/uploads/2024/10/Estrara_Raporto_2023_UEA.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_2024_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in Arusha",
      "value": 854,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "2024",
      "definition": "The first World Esperanto Congress in Africa",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_2025_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in Brno",
      "value": 1132,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "2025",
      "definition": "110th World Esperanto Congress",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "world_congress_2026_participants",
      "section": "congresses",
      "metric": "Participants of the World Congress in Graz",
      "value": 1138,
      "value_low": null,
      "value_high": null,
      "unit": "participants",
      "date": "2026",
      "definition": "111th World Esperanto Congress",
      "method": "reported",
      "sources": [
        {
          "title": "UEA, list of World Congresses",
          "url": "https://uea.org/kongresoj/listo"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "alphabet_letters",
      "section": "language",
      "metric": "Letters of the Esperanto alphabet",
      "value": 28,
      "value_low": null,
      "value_high": null,
      "unit": "letters",
      "date": "1887",
      "definition": "5 vowels and 23 consonants, one sound each",
      "method": "reported",
      "sources": [
        {
          "title": "Fundamento de Esperanto, grammar in English",
          "url": "https://www.akademio-de-esperanto.org/fundamento/gramatiko_angla.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "grammar_rules",
      "section": "language",
      "metric": "Rules of the Fundamental Grammar",
      "value": 16,
      "value_low": null,
      "value_high": null,
      "unit": "rules",
      "date": "1887",
      "definition": "First printed in the Unua Libro (1887), binding since the Fundamento (1905)",
      "method": "reported",
      "sources": [
        {
          "title": "Fundamento de Esperanto, grammar in English",
          "url": "https://www.akademio-de-esperanto.org/fundamento/gramatiko_angla.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "grammatical_endings",
      "section": "language",
      "metric": "Grammatical endings",
      "value": 11,
      "value_low": null,
      "value_high": null,
      "unit": "endings",
      "date": "",
      "definition": "Endings counted as grammatical elements by the Academy of Esperanto",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, Akademia Vortaro: explanations",
          "url": "https://www.akademio-de-esperanto.org/akademia_vortaro/klarigoj.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "correlatives",
      "section": "language",
      "metric": "Correlatives (table words)",
      "value": 45,
      "value_low": null,
      "value_high": null,
      "unit": "words",
      "date": "",
      "definition": "5 beginnings × 9 endings",
      "method": "reported",
      "sources": [
        {
          "title": "PMEG, Tabelvortoj",
          "url": "https://bertilow.com/pmeg/gramatiko/tabelvortoj/bazaj_reguloj.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "official_prefixes",
      "section": "language",
      "metric": "Official prefixes",
      "value": 10,
      "value_low": null,
      "value_high": null,
      "unit": "prefixes",
      "date": "1929",
      "definition": "Nine from the Fundamento; mis- official since 1929",
      "method": "reported",
      "sources": [
        {
          "title": "PMEG, Prefiksoj",
          "url": "https://bertilow.com/pmeg/vortfarado/afiksoj/prefiksoj/index.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "official_suffixes",
      "section": "language",
      "metric": "Official suffixes",
      "value": 31,
      "value_low": null,
      "value_high": null,
      "unit": "suffixes",
      "date": "1953",
      "definition": "28 from the Fundamento, -aĉ- (1909), -ism- (1919) and -end- (1953); plus 6 participle suffixes",
      "method": "reported",
      "sources": [
        {
          "title": "PMEG, Sufiksoj",
          "url": "https://bertilow.com/pmeg/vortfarado/afiksoj/sufiksoj/index.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "fundamental_elements",
      "section": "language",
      "metric": "Fundamental word elements",
      "value": 2768,
      "value_low": null,
      "value_high": null,
      "unit": "elements",
      "date": "1905",
      "definition": "Word elements of the Fundamento, as counted by the Academy",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, Akademia Vortaro: explanations",
          "url": "https://www.akademio-de-esperanto.org/akademia_vortaro/klarigoj.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "official_elements_to_9th_addition",
      "section": "language",
      "metric": "Official word elements up to the 9th Official Addition",
      "value": 4953,
      "value_low": null,
      "value_high": null,
      "unit": "elements",
      "date": "2007",
      "definition": "2,768 Fundamental elements and 2,185 elements made official in the Additions from 1909 to 2007",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, Akademia Vortaro: explanations",
          "url": "https://www.akademio-de-esperanto.org/akademia_vortaro/klarigoj.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "official_elements_in_additions_to_2007",
      "section": "language",
      "metric": "Word elements made official in the Additions, 1909–2007",
      "value": 2185,
      "value_low": null,
      "value_high": null,
      "unit": "elements",
      "date": "1909/2007",
      "definition": "Official elements beyond the Fundamento, up to the 9th Addition",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, Akademia Vortaro: explanations",
          "url": "https://www.akademio-de-esperanto.org/akademia_vortaro/klarigoj.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "official_additions",
      "section": "language",
      "metric": "Official Additions to the vocabulary",
      "value": 10,
      "value_low": null,
      "value_high": null,
      "unit": "additions",
      "date": "1909/2023",
      "definition": "Official Additions (Oficialaj Aldonoj), the 10th approved on 24 September 2023",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, 10th Official Addition",
          "url": "https://www.akademio-de-esperanto.org/decidoj/10oa.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "first_addition_elements",
      "section": "language",
      "metric": "Word elements in the 1st Official Addition",
      "value": 805,
      "value_low": null,
      "value_high": null,
      "unit": "elements",
      "date": "1909",
      "definition": "Elements made official in 1909",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, 10th Official Addition",
          "url": "https://www.akademio-de-esperanto.org/decidoj/10oa.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "tenth_addition_roots",
      "section": "language",
      "metric": "Roots in the 10th Official Addition",
      "value": 420,
      "value_low": null,
      "value_high": null,
      "unit": "roots",
      "date": "2023",
      "definition": "Roots made official on 24 September 2023",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, 10th Official Addition",
          "url": "https://www.akademio-de-esperanto.org/decidoj/10oa.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "official_elements_with_10th_addition",
      "section": "language",
      "metric": "Official word elements including the 10th Addition",
      "value": 5373,
      "value_low": null,
      "value_high": null,
      "unit": "elements",
      "date": "2023",
      "definition": "4,953 elements up to 2007 plus 420 roots of the 10th Addition",
      "method": "our sum",
      "sources": [
        {
          "title": "Akademio de Esperanto, 10th Official Addition",
          "url": "https://www.akademio-de-esperanto.org/decidoj/10oa.html"
        },
        {
          "title": "Akademio de Esperanto, Akademia Vortaro: explanations",
          "url": "https://www.akademio-de-esperanto.org/akademia_vortaro/klarigoj.html"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "official_roots_revo",
      "section": "language",
      "metric": "Roots marked as official in the ReVo dictionary",
      "value": 5328,
      "value_low": null,
      "value_high": null,
      "unit": "roots",
      "date": "2026-10",
      "definition": "One root per ReVo entry marked as official; a different unit from the Academy's word elements",
      "method": "our count",
      "sources": [
        {
          "title": "Esperantopedia, list of official roots",
          "url": "https://esperantopedia.org/dictionary/oficialaj-radikoj/"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "unua_libro_roots",
      "section": "language",
      "metric": "Roots in the Unua Libro",
      "value": 917,
      "value_low": null,
      "value_high": null,
      "unit": "roots",
      "date": "1887-07-26",
      "definition": "Vocabulary of the first Esperanto textbook, published in Warsaw",
      "method": "reported",
      "sources": [
        {
          "title": "Korĵenkov, Zamenhof: The Life, Works and Ideas of the Author of Esperanto",
          "url": "http://www.esperantic.org/wp-content/uploads/2016/06/LLZ-Bio-En.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "unua_libro_pages",
      "section": "language",
      "metric": "Pages of the Unua Libro",
      "value": 42,
      "value_low": null,
      "value_high": null,
      "unit": "pages",
      "date": "1887-07-26",
      "definition": "Length of the first Esperanto textbook",
      "method": "reported",
      "sources": [
        {
          "title": "Korĵenkov, Zamenhof: The Life, Works and Ideas of the Author of Esperanto",
          "url": "http://www.esperantic.org/wp-content/uploads/2016/06/LLZ-Bio-En.pdf"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "ilei_countries",
      "section": "organisations",
      "metric": "Countries with ILEI",
      "value": 70,
      "value_low": null,
      "value_high": null,
      "unit": "countries",
      "date": "2019",
      "definition": "Countries where the International League of Esperanto Teachers (ILEI) was present",
      "method": "reported",
      "sources": [
        {
          "title": "Vikipedio, Internacia Ligo de Esperantistaj Instruistoj",
          "url": "https://eo.wikipedia.org/wiki/Internacia_Ligo_de_Esperantistaj_Instruistoj"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "sat_members_1929",
      "section": "organisations",
      "metric": "Members of SAT",
      "value": 6500,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "1929/1930",
      "definition": "Members of Sennacieca Asocio Tutmonda; the source says over 6,500",
      "method": "reported",
      "sources": [
        {
          "title": "Wikipedia, Sennacieca Asocio Tutmonda",
          "url": "https://en.wikipedia.org/wiki/Sennacieca_Asocio_Tutmonda"
        }
      ],
      "checked": "2026-10-08"
    },
    {
      "id": "academy_members",
      "section": "organisations",
      "metric": "Members of the Academy of Esperanto",
      "value": 43,
      "value_low": null,
      "value_high": null,
      "unit": "members",
      "date": "2026-06",
      "definition": "Members of the Akademio de Esperanto, as listed in June 2026",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, Membroj kaj korespondantoj",
          "url": "https://www.akademio-de-esperanto.org/akademio/index.php?title=Membroj_kaj_korespondantoj"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "academy_correspondents",
      "section": "organisations",
      "metric": "Correspondents of the Academy of Esperanto",
      "value": 9,
      "value_low": null,
      "value_high": null,
      "unit": "correspondents",
      "date": "2026-06",
      "definition": "Corresponding members of the Akademio de Esperanto, as listed in June 2026",
      "method": "reported",
      "sources": [
        {
          "title": "Akademio de Esperanto, Membroj kaj korespondantoj",
          "url": "https://www.akademio-de-esperanto.org/akademio/index.php?title=Membroj_kaj_korespondantoj"
        }
      ],
      "checked": "2026-11-05"
    },
    {
      "id": "onb_planned_language_volumes",
      "section": "books",
      "metric": "Printed volumes in the Department of Planned Languages, Austrian National Library",
      "value": 45000,
      "value_low": null,
      "value_high": null,
      "unit": "volumes",
      "date": "2025-06-18",
      "definition": "About 45,000 printed volumes on about 500 planned languages, Esperanto among them; a library holding, not a count of Esperanto titles",
      "method": "reported",
      "sources": [
        {
          "title": "Austrian National Library, Department of Planned Languages (archived 18 Jun 2025)",
          "url": "https://webarchiv.onb.ac.at/web/20250618023111/https://www.onb.ac.at/en/departments/department-of-planned-languages"
        }
      ],
      "checked": "2026-10-08"
    }
  ]
}