|TLD type||Country code top-level domain|
|Registry||NIC.IO (run by Internet Computer Bureau)|
|Sponsor||IO Top Level Domain Registry (Cable and Wireless)|
|Intended use||Entities connected with British Indian Ocean Territory|
|Actual use||Popular with startup companies; little of anything related to the territory itself.|
|Registration restrictions||None for 2nd level registrations; 3rd level registrant must be resident of British Indian Ocean Territory|
|Structure||Registrations are taken directly at the second level or at third level beneath various 2nd-level labels|
|Documents||Terms & Conditions; Rules|
|Dispute policies||Dispute Resolution Policy|
The .io domain extension has existed since 1997, and has grown steadily in popularity ever since.
Labels for .io domains may only contain alphanumeric characters and hyphens and must be between 3 and 63 characters long. Domain names cannot begin with, or end with, a hyphen symbol, and may not contain two consecutive hyphens. The entire domain name may not contain more than 253 characters.
The right to administer domain names is given to approved organisations by the Internet Assigned Numbers Authority (IANA). The Internet Computer Bureau (ICB) administers .io domains. This domain name registry is a British company, and operates for this purpose under the name NIC.IO. The company also holds the rights to sell .sh-domain and .ac-domains, the top-level domains for the South Atlantic islands of Saint Helena and Ascension, respectively.
Registration and restrictions
Both individuals and organisations are allowed to register .io-domains.
In order to register .io domains you do not need to be registered or established in the British Indian Ocean territory. In order to register third-level domains such as xyz.com.io you have to be an inhabitant of the area. Any second-level domains used by NIC.IO and top-level domains can not be used as a third-level domain. For example, the domain "com.com.io", "org.com.io" and "biz.com.io" are all restricted.
Domain names in .io may not be used "for any purpose that is sexual or pornographic or that is against the statutory laws of any Nation". Breaching this requirement "NIC.IO reserves the right to immediately deactivate the offending registration".
Dot-io domains may be registered for a minimum of one year, and a maximum of 10 years.
Domain names in .io are currently priced higher than those in other TLDs. Registering available .io-domains starts from around £30 / $32.88 US per year.
The .io-domain has considerable usage unrelated to the British Indian Ocean Territory.
"Nowadays, a lot of TLDs are used without any relation to the original country, such as .ly, .io, .me."— Jens Segers - Founder of Auki.io
"We took it because it refers to ‘input-output’. And our customers (mostly tech savvy people) understand it like so."— Ben Verbeken - Seats.io CEO
.io has also been taken as an abbreviation of "Internet organization". In addition, .io domains are often used for open source projects, APIs (such as put.io API and pen.io API) and online services.
Many recently popular games also use the .io domain such as agar.io, slither.io, wings.io, vertix.io, limax.io, supersnake.io, wilds.io, vanar.io, tankwars.io, tankar.io, lazerdrive.io, cursors.io and diep.io. You can also find versions of these games on the app store and google play.
One of the main reasons behind this popularity is the availability of .io domains: Though it is often hard to find a fitting .com domain, there are plenty of corresponding .io domains available that have not yet been registered. This may be due in part to registrations being suppressed by the relatively high price of .io domain names.
According to a Gigaom interview with Paul Kane, chairman of the Internet Computer Bureau, the domain name registry is required to give some of its profits to the British government, for administration of the British Indian Ocean Territory. As no indigenous Chagossians remain in the territory, the only residents being about 4,000 United States military personnel and contractors, it is contended that the indigenous Chagossians do not receive any monetary benefit from the sale of the domain names.
After being questioned as a result of the interview, the British Government denied receiving any funds from the sale of .io domain names, and argued that consequently, the profits could not be shared with the Chagossians.
- IDN Code Points Policy for the .IO Top Level Domain (PDF), NIC.IO
- "IANA — .io Domain Delegation Data". iana.org.
- "Geotargetable domains". Google. Retrieved 6 May 2013.
- "NIC.IO - The Indian Ocean .IO Domain Registry and Network Information Centre - Whois Search". Retrieved 2014-12-29.
- ".IO Domain". Retrieved 2014-10-29.
- "Eigenschaften einer .io-Domain" (in German). united-domains.de.
- RFC 1035, Domain names--Implementation and specification, P. Mockapetris (Nov 1987)
- "Internet Computer Bureau".
- "RULES for the .IO Domain and Sub-Domains".
- "NIC.IO - The Indian Ocean .IO Domain Registry and Network Information Centre". nic.io.
- David Meyer. "The dark side of .io: How the U.K. is making web domain profits from a shady Cold War land deal". gigaom.com.
- "Popularity with startups".
- "IO Domains in Alexa Top 1 Million.". Retrieved 27 May 2015.
- Beattie, Russell (2013-02-12). "The rise of .io domains for well crafted web services". Retrieved 2014-04-24.
There's lots of open source projects (Redis, Brackets, Launcher), a few mobile-app landing pages (Avocado, X-Ray), a ton of new web apps and services, several conference pages (Lightning, Renaissance, Resonate) and a few older companies or organizations who've changed their name to take advantage of a cleaner .io name.
- "CIA World Factbook - British Indian Ocean Territory", Central Intelligence Agency, 21 May 2014
- "House of Lords". parliament.uk.
- David Meyer. "UK government denies receiving .io domain profits". gigaom.com.