{
 "id": "ep43n42p6z",
 "slug": "io-ep43n42p6z",
 "title": ".io",
 "updated": "2026-10-15",
 "topic_path": [
  {
   "id": "technology",
   "label": "Technology and the built world",
   "api_url": "https://www.edgepedia.org/api/v1/topics/technology"
  },
  {
   "id": "technology.computing",
   "label": "Computing and digital systems",
   "api_url": "https://www.edgepedia.org/api/v1/topics/technology.computing"
  },
  {
   "id": "technology.computing.networks",
   "label": "Networks and security",
   "api_url": "https://www.edgepedia.org/api/v1/topics/technology.computing.networks"
  },
  {
   "id": "technology.computing.networks.security-governance",
   "label": "Security governance and internet policy",
   "api_url": "https://www.edgepedia.org/api/v1/topics/technology.computing.networks.security-governance"
  },
  {
   "id": "technology.computing.networks.internet-governance",
   "label": "Internet governance",
   "api_url": "https://www.edgepedia.org/api/v1/topics/technology.computing.networks.internet-governance"
  },
  {
   "id": "technology.computing.networks.internet-governance.ip-governance-and-critical-resources",
   "label": "IP address and critical internet resource governance",
   "api_url": "https://www.edgepedia.org/api/v1/topics/technology.computing.networks.internet-governance.ip-governance-and-critical-resources"
  }
 ],
 "geo": [
  {
   "id": "geo.other.t1946.technology.computing",
   "label": "Other (Canada, Oceania, polar regions, oceans) · 1946 to 2000: Computing and digital systems",
   "api_url": "https://www.edgepedia.org/api/v1/geo/geo.other.t1946.technology.computing",
   "path": [
    {
     "id": "geo.other",
     "label": "Other (Canada, Oceania, polar regions, oceans)",
     "api_url": "https://www.edgepedia.org/api/v1/geo/geo.other"
    },
    {
     "id": "geo.other.t1946",
     "label": "Other (Canada, Oceania, polar regions, oceans) · 1946 to 2000",
     "api_url": "https://www.edgepedia.org/api/v1/geo/geo.other.t1946"
    },
    {
     "id": "geo.other.t1946.technology",
     "label": "Technology and the built world",
     "api_url": "https://www.edgepedia.org/api/v1/geo/geo.other.t1946.technology"
    },
    {
     "id": "geo.other.t1946.technology.computing",
     "label": "Computing and digital systems",
     "api_url": "https://www.edgepedia.org/api/v1/geo/geo.other.t1946.technology.computing"
    }
   ]
  }
 ],
 "excerpt": ".io, the Io domain, is the country-code top-level domain for the British Indian Ocean Territory, delegated in 1997, managed by a UK company, and widely used by startups.",
 "snippet": ".io, the Io domain, is the country-code top-level domain for the British Indian Ocean Territory, delegated in 1997, managed by a UK company, and widely used by startups.",
 "node": "technology.computing.networks.internet-governance.ip-governance-and-critical-resources",
 "markdown": "# .io\n\n**.io** is the country-code top-level domain (ccTLD) assigned to the [British Indian Ocean Territory](https://www.edgepedia.org/british-indian-ocean-territory), the [Chagos Archipelago](https://www.edgepedia.org/chagos-archipelago) in the central Indian Ocean. It was delegated by the [Internet Assigned Numbers Authority](https://www.edgepedia.org/internet-assigned-numbers-authority) (IANA) on 16 September 1997 and is managed by Internet Computer Bureau Limited, a UK company whose registry services operate under the NIC.IO name<sup>[1](https://www.iana.org/domains/root/db/io.html)</sup><sup> • </sup><sup>[2](https://nic.io/legal/legal_master.html)</sup>. Although it codes for a territory with no permanent civilian population, .io has become one of the most widely used domain endings in the technology sector, where the letters are read as \"input/output\"<sup>[3](https://www.registros.com/en/blog/dominios/startups-and-the-io-domain-trend/)</sup>.\n\n| Key fact | Detail |\n|---|---|\n| Type | Country-code top-level domain for the British Indian Ocean Territory<sup>[1](https://www.iana.org/domains/root/db/io.html)</sup> |\n| Delegated | 16 September 1997 (IANA registration date)<sup>[1](https://www.iana.org/domains/root/db/io.html)</sup> |\n| Manager | Internet Computer Bureau Limited, c/o Sure (Diego Garcia) Limited, Diego Garcia; registry site nic.io, WHOIS at whois.nic.io<sup>[1](https://www.iana.org/domains/root/db/io.html)</sup> |\n| Scale | More than 1.6 million .io websites as of October 2024<sup>[4](https://www.theregister.com/off-prem/2024/10/10/the-io-domain-isnt-going-anywhere-in-the-next-few-years/479311)</sup> |\n| Ownership change | Afilias Ltd. bought .IO for $70 million in 2017<sup>[5](https://www.oecdwatch.org/complaint/chagos-refugees-group-united-kingdom-et-al-vs-internet-computer-bureau-limited/)</sup> |\n| Startup share | 2% of Y Combinator startup domains in 2018, rising to 11% in a later batch<sup>[6](https://www.namecheap.com/blog/why-many-startups-dont-use-com-domains/)</sup> |\n| Retirement rule | If \"IO\" is removed from ISO 3166-1, ICANN's retirement policy starts a five-year phase-out window, extendable under certain circumstances<sup>[7](https://www.icann.org/es/blogs/details/the-chagos-archipelago-and-the-io-domain-14-11-2024-en)</sup> |\n\n## Delegation and management\n\nThe IANA delegation record lists Internet Computer Bureau Limited as ccTLD manager, with an administrative contact in [Diego Garcia](https://www.edgepedia.org/diego-garcia) and a technical contact in Orpington, Kent, in the United Kingdom. The record shows four name servers (a0, a2, b0, and c0.nic.io), registration services at www.nic.io, and a WHOIS server at whois.nic.io; the record was last updated on 18 January 2023<sup>[1](https://www.iana.org/domains/root/db/io.html)</sup>. The registry's own terms state that \"IO Top Level Domain Registry\" and \"NIC.IO\" are trading names of Internet Computer Bureau Limited<sup>[2](https://nic.io/legal/legal_master.html)</sup>.\n\nThe territory itself has an unusual history. The Chagos Archipelago was uninhabited until the late 18th century, when the French established copra plantations using slave labor in 1793; the islands have been British territory since 1814, when they were ceded with [Mauritius](https://www.edgepedia.org/mauritius). The British Indian Ocean Territory was constituted in 1965 by an Order in Council under the Royal Prerogative<sup>[8](https://www.biot.gov.io/about/history/)</sup>. A 2023 academic analysis noted that .io is an Indian Ocean ccTLD whose delegation is held outside the control of the relevant government or former inhabitants, with management and profit sitting with ICB<sup>[9](https://www.tandfonline.com/doi/pdf/10.1080/23738871.2023.2238723)</sup>.\n\n## The Chagos handover and the retirement question\n\nIn October 2024 the governments of the United Kingdom and Mauritius announced a treaty to transfer sovereignty over the British Indian Ocean Territory to Mauritius, raising the question of what happens to a domain that exists only because of that territory's ISO country code<sup>[4](https://www.theregister.com/off-prem/2024/10/10/the-io-domain-isnt-going-anywhere-in-the-next-few-years/479311)</sup><sup> • </sup><sup>[10](https://pdf.hoganlovells.com/en/publications/domain-name-news-october-2024)</sup>.\n\nThe mechanism is indirect. ICANN relies on the [ISO 3166-1](https://www.edgepedia.org/iso-3166-1) standard to determine which country-code domains are eligible, and an ICANN blog post by Kim Davies, Vice President of IANA Services and President of Public Technical Identifiers, stated that \"IO\" persisted in the standard with no change as a result of the sovereignty announcement. If \"IO\" is removed as an assigned code, ICANN's retirement policy applies: a five-year window opens during which usage of the domain must be phased out, and that window may be extended under certain circumstances<sup>[7](https://www.icann.org/es/blogs/details/the-chagos-archipelago-and-the-io-domain-14-11-2024-en)</sup>. An ICANN spokesperson told [The Register](https://www.edgepedia.org/the-register) that multiple outcomes are possible depending on the nature of any ISO change, including maintaining an operational nexus with Mauritius, and noted that the ISO code also serves non-domain uses such as customs, passports, and banking<sup>[4](https://www.theregister.com/off-prem/2024/10/10/the-io-domain-isnt-going-anywhere-in-the-next-few-years/479311)</sup>.\n\n## Adoption by startups and developers\n\nThe extension's popularity with technology companies rests on a reading of the letters as I/O, the input/output abbreviation familiar in software development<sup>[3](https://www.registros.com/en/blog/dominios/startups-and-the-io-domain-trend/)</sup>. Early devtools, infrastructure startups, and hosting platforms built brands on .io names, and the association held across technology cycles<sup>[11](https://dotappraisals.io/blog/dot-io-review)</sup>.\n\nThe numbers show the trajectory. Among 1,587 funded [Y Combinator](https://www.edgepedia.org/y-combinator) startups analyzed in one survey, .io was the leading alternative TLD with 80 companies, a 5.2% share, more than .co and .ai combined<sup>[12](https://domainsproject.org/blog/io-13-million-domains-zero-residents)</sup>. Namecheap's analysis of Y Combinator batches found .io at 2% of startup domain share in 2018, rising steadily to 11%<sup>[6](https://www.namecheap.com/blog/why-many-startups-dont-use-com-domains/)</sup>. A funding tracker by Atom covering 154 disclosed rounds on .io recorded $9.8 billion in announced capital with a median round of $15 million; among rounds with a resolved vertical, SaaS accounted for 28.5%, AI 17.9%, cybersecurity 15.4%, and fintech 14.6%<sup>[13](https://www.atom.com/startup-funding/extension/io)</sup>. The DomainsProject dataset counted 13,234,503 records across 1,592,882 unique base domains<sup>[12](https://domainsproject.org/blog/io-13-million-domains-zero-residents)</sup>.\n\nThe letters also spawned a game genre. [Agar.io](https://www.edgepedia.org/agar-io) drew 192 million visits in 2017, and the .io suffix became a recognizable label for simple browser multiplayer games<sup>[12](https://domainsproject.org/blog/io-13-million-domains-zero-residents)</sup>.\n\n## Disputes over the domain's governance\n\nThe domain's connection to the Chagos Islands' history has drawn formal complaints. On 29 July 2021 the Chagos Refugees Group United Kingdom, supported by the Crypto Currency Resolution Trust of the Bahamas, filed a complaint at the Irish National Contact Point for the OECD Guidelines against Afilias Ltd. and its subsidiaries 101 Domains GRS Limited and Internet Computer Bureau Limited. The complainants, descendants of islanders forcibly deported by Britain, sought restitution and return of .IO, alleging that Afilias acquired the domain knowing its connection to human rights abuses; the [United Nations General Assembly](https://www.edgepedia.org/united-nations-general-assembly), African Union, and [International Court of Justice](https://www.edgepedia.org/international-court-of-justice) have all found Britain's deportation and continued occupation of the archipelago to be a serious violation of international law<sup>[5](https://www.oecdwatch.org/complaint/chagos-refugees-group-united-kingdom-et-al-vs-internet-computer-bureau-limited/)</sup>. After an OECD human rights ruling, a group of displaced [Chagossians](https://www.edgepedia.org/chagossians) announced it would ask ICANN to redelegate the domain<sup>[14](https://domainincite.com/29173-group-to-seek-io-tld-takeover-after-oecd-human-rights-ruling)</sup>.\n\n## References\n\n1. [.io Domain Delegation Data, IANA Root Zone Database](https://www.iana.org/domains/root/db/io.html)\n2. [NIC.IO Terms and Conditions, Internet Computer Bureau Limited](https://nic.io/legal/legal_master.html)\n3. [Start-Ups and the .io Domain Trend, Blog Registros.com](https://www.registros.com/en/blog/dominios/startups-and-the-io-domain-trend/)\n4. [The .io domain isn't going anywhere in the next few years, The Register (10 October 2024)](https://www.theregister.com/off-prem/2024/10/10/the-io-domain-isnt-going-anywhere-in-the-next-few-years/479311)\n5. [Chagos Refugees Group United Kingdom, et al. vs. Internet Computer Bureau Limited, OECD Watch](https://www.oecdwatch.org/complaint/chagos-refugees-group-united-kingdom-et-al-vs-internet-computer-bureau-limited/)\n6. [Over 50% of new startups don't use .COM domains, Namecheap Blog](https://www.namecheap.com/blog/why-many-startups-dont-use-com-domains/)\n7. [The Chagos Archipelago and the .io domain, ICANN blog (14 November 2024)](https://www.icann.org/es/blogs/details/the-chagos-archipelago-and-the-io-domain-14-11-2024-en)\n8. [History, British Indian Ocean Territory](https://www.biot.gov.io/about/history/)\n9. [Self-regulation, internet domains and Indian Ocean territories, Journal of Cyber Policy](https://www.tandfonline.com/doi/pdf/10.1080/23738871.2023.2238723)\n10. [Domain Name News October 2024, Hogan Lovells](https://pdf.hoganlovells.com/en/publications/domain-name-news-october-2024)\n11. [.io Domain Review: Still the Default for Devtools in 2026, dotappraisals](https://dotappraisals.io/blog/dot-io-review)\n12. [.io: 13.2 Million Domains, Zero Residents, and the Tech Industry's Most Precarious TLD, DomainsProject](https://domainsproject.org/blog/io-13-million-domains-zero-residents)\n13. [Startups on .io: funding, verticals and naming, Atom](https://www.atom.com/startup-funding/extension/io)\n14. [Group to seek .io TLD takeover after OECD human rights ruling, Domain Incite](https://domainincite.com/29173-group-to-seek-io-tld-takeover-after-oecd-human-rights-ruling)\n\n---\n*Topic: Encyclopedia › Technology and the built world › Computing and digital systems › Networks and security › Security governance and internet policy › Internet governance › IP address and critical internet resource governance*\n\n*Initially written Sep 17, 2026 · Reviewed: Oct 15, 2026 · Edited: Oct 15, 2026 · Last review: Oct 15, 2026*\n\n*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*\n\nLicense: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license\n",
 "same_as": [],
 "url": "https://www.edgepedia.org/io-ep43n42p6z",
 "markdown_url": "https://www.edgepedia.org/io-ep43n42p6z.md",
 "license": {
  "name": "Edgepedia Community License 1.0",
  "url": "https://www.edgepedia.org/edgepedia/license",
  "summary": "Free with credit, commercial use included. AI training is open to everyone. For other uses, organizations over USD 100M in revenue or 100M monthly users license separately.",
  "spdx": "LicenseRef-Edgepedia-Community-1.0"
 },
 "credit": "\".io\", Edgepedia (EdgeChat), https://www.edgepedia.org/io-ep43n42p6z. Edgepedia Community License 1.0.",
 "credit_md": "\"[.io](https://www.edgepedia.org/io-ep43n42p6z)\", Edgepedia (EdgeChat), [https://www.edgepedia.org/io-ep43n42p6z](https://www.edgepedia.org/io-ep43n42p6z). [Edgepedia Community License 1.0](https://www.edgepedia.org/edgepedia/license).",
 "credit_html": "\"<a href=\"https://www.edgepedia.org/io-ep43n42p6z\">.io</a>\", Edgepedia (EdgeChat), <a href=\"https://www.edgepedia.org/io-ep43n42p6z\">https://www.edgepedia.org/io-ep43n42p6z</a>. <a href=\"https://www.edgepedia.org/edgepedia/license\">Edgepedia Community License 1.0</a>.",
 "speakable": ".io, the Io domain, is the country-code top-level domain for the British Indian Ocean Territory, delegated in 1997, managed by a UK company, and widely used by startups."
}