The .io domain, and its one real question
Half the dev tools you use sit on a .io. It's the closest thing tech has to a default extension. It also belongs to a territory that may not exist much longer, which is worth understanding before you commit.
Reviewed May 2026
.io shows up everywhere in software: side projects, funded startups, infrastructure companies, status pages. For a developer audience it reads as 'this is a technical product' without anyone having to say so. That reputation took about a decade to build, and it's strong enough now that plenty of people register a .io without knowing what the letters stand for or where the domain actually comes from.
Where .io comes from
.io is the country-code domain for the British Indian Ocean Territory, a scattering of atolls in the middle of the Indian Ocean with no permanent civilian population. Developers didn't adopt it for the geography. They adopted it because 'io' is input/output, the most basic idea in computing, and because in the late 2000s .com already felt exhausted while .io sat there short and unclaimed. The meaning was a happy accident. The look stuck.
It's run as a commercial operation. The registry has passed through a few hands and is now part of Identity Digital, one of the larger registry companies. That's worth knowing, because it means .io isn't some quaint government project; it's a product, priced like one.
The Chagos handover
Here's the part most people registering a .io have never heard. The British Indian Ocean Territory is disputed land. The UK split the Chagos Islands off from Mauritius in the 1960s and removed the people living there to clear the way for a military base. Mauritius never accepted it, and in 2024 the UK agreed to hand sovereignty back.
Country-code domains are tied to a country's two-letter code in the ISO standard. If the territory stops existing as a separate entity, the IO code can eventually be withdrawn, and historically that has meant the domain is retired. It happened to .yu when Yugoslavia broke up, and to .cs before that. Those retirements ran over several years, not overnight.
.io is a different scale of problem, though. It isn't a few thousand domains; it's millions, a lot of them attached to real companies. Nobody who runs the internet's plumbing wants to be the one who deletes them. The honest summary: there is genuine uncertainty about .io's long-term future, the mechanism that could end it is real, and the likeliest outcomes are a long managed transition or an arrangement that keeps it alive, not a sudden shutoff. Build with that in mind rather than ignoring it.
What it costs
.io has never been cheap. It sits above .com and below .ai, in the range registrars are happy to charge a premium for, because the buyers are mostly businesses who'll pay it. Check the live price at registration; expect more than a .com, and look at the renewal, not just the first year.
Should you use one
For a developer tool, a side project, an infrastructure company, a status page, .io still does its job. It signals technical, it's recognised, and the .com for your name is probably gone anyway. For a product aimed at people who don't work in software, the signal is wasted and the sovereignty question is a real if small risk; a .com serves you better. And if you do want a .io, know going in that the short ones are gone; you'll be coining a name, not claiming a word.