.io
.io domain checker
Check a .io — and read the part about its future before you build on it.
Checked against the registry over RDAP, alongside every other ending and every social handle.
What .io is
The country-code domain for the British Indian Ocean Territory, adopted by the technology industry because "io" reads as input/output. Registration is open worldwide with no local presence requirement, and it has been a default for developer tools and startups for well over a decade.
Who it suits
Developer tools, APIs, technical products and anything whose audience finds it through a link rather than by remembering a name out loud. In that world .io carries no penalty at all and arguably signals the right thing.
The catch
Its long-term future is a genuinely open question. The United Kingdom agreed in 2024 to transfer sovereignty of the Chagos Archipelago to Mauritius, and a country-code domain is tied to the territory it represents. ICANN's process for retiring a ccTLD runs over a period of years and, as of this writing, no retirement of .io has been announced or begun. Nobody credible expects .io to vanish next year. But if you are naming something you intend to still be running in fifteen years, it is a reason to hold the .com too.
Common questions
Is .io going away?
No announcement has been made and no retirement process has begun. The uncertainty is real but slow-moving: ICANN's own framework for retiring a country-code domain runs over several years with a long transition. Treat it as a reason to own the matching .com, not a reason to panic.
Does .io hurt SEO?
No. Google treats .io as a generic ending rather than tying it to a country, so you are not geo-restricted by using it.
Do I need to be based anywhere in particular?
No. There is no residency or presence requirement, and registrations go through ordinary registrars.