.io domain availability checker
Type a name to see whether its .io is registered, asked live of the .io registry. If it is taken, the same name is checked in 17 other extensions below it. A free .io costs from $28.12 the first year but renews at $51.80, and about a third of the .io names people checked here (36%) were already registered.
Free, no sign-in. Free names show the price and a Register button; checkout confirms the name with the registrar again before you pay. Every extension at once: domain availability checker; mixed extensions in one list: bulk domain checker.
Six .io checks, 4 November 2026
Three names we know are registered and three random strings, sent through this checker on the live site. 3 of 3 known names answered taken and 3 of 3 random strings free.
| Domain | What it is | Answer | Time |
|---|---|---|---|
| github.io | Known site | taken | 173 ms |
| itch.io | Known site | taken | 173 ms |
| socket.io | Known site | taken | 173 ms |
| ussiysj7y5k.io | Random string | free | 423 ms |
| rtbnbctuxe1.io | Random string | free | 355 ms |
| k6odtyz4lfr.io | Random string | free | 406 ms |
Time is from sending the check to the answer arriving, all six in one run. A taken answer can come from our record of names found registered in the past 7 days, which is why some known names answer fastest; a free answer is always asked of the registry.
.io at a glance
- Registry
- Internet Computer Bureau Limited; technical operator Internet Computer Bureau Ltd
- This checker asks
- The .io registry's WHOIS server (whois.nic.io), because .io has no RDAP server in IANA's list; if WHOIS does not answer, the DNS
- DNSSEC
- Signed
- First year
- $28.12 at Porkbun, $28.89 at Dynadot
- Renews at
- $51.80 at Porkbun, $53.50 at Dynadot
- Five years
- $235.32 at Porkbun
- Taken on domhaul
- 36% of 77 names checked since 4 August 2026
- Who can register
- Anyone, through a registrar
- Name length
- 3 to 63 characters on open sale. The registry allocates 1- and 2-character names separately.
- Minimum term
- 1 year minimum
Registry: IANA root zone database. Prices: the lowest standard (non-premium) quote, USD, as of 24 October 2026. Taken: the share of distinct names people checked on domhaul that were already registered. Its history, pricing and the Chagos question are in the .io guide.
.io availability questions
Is the .io domain going away?
Not soon. .io is the country code of the British Indian Ocean Territory, and in October 2024 the UK agreed to hand the Chagos Islands to Mauritius. If the IO code is removed from the ISO 3166-1 list, ICANN's retirement process gives the registry five years to wind it down, and past retirements ran slowly. On 4 November 2026 .io was in the root zone and registering normally; it is a risk for a name you mean to keep for decades.
What does a .io cost to keep?
$28.12 the first year at Porkbun, then $51.80 a year; Dynadot was $28.89 and $53.50 (24 October 2026). The renewal is 1.8 times the first year, so five years come to $235.32. Judge a .io on $51.80 a year; .dev renews at $12.87 and .co at $31.20.
Can I register a one- or two-letter .io?
Not through a normal checkout. The registry's rules hold 1- and 2-character names back and allocate them separately, so plan on 3 characters or more. Even then short .io names are scarce: github.io, itch.io and socket.io answered taken on 4 November 2026, and three-letter words went years ago.
Why do developer tools use .io?
Programmers read io as input/output, and around 2010 a two-letter extension with few names taken was an easy way out when the matching .com was gone. GitHub Pages (github.io), itch.io and socket.io made it the default for developer projects. Nothing in the rules ties it to tech: anyone can register one for any site.
Check another extension
.com .ai .co .app .dev .net .org .xyz .gg. Taken everywhere? The AI domain name generator suggests names and checks each one live. Look up a taken name's registrar with the WHOIS lookup, when it runs out with the domain expiration checker, or what it is worth in the domain value calculator.