The favourite extension of tech startups and developer tools. Check your .io name, plus .ai, .dev and .com alternatives, in one search.
.io started as the country code for the British Indian Ocean Territory but became the go-to extension for SaaS companies, APIs and developer tools because 'I/O' means input/output. Good .com names are scarce, so a short .io is often the cleanest option for a new product. Search your name to see availability across .io and the other extensions tech brands use most.
Quick answers to the most common questions.
Yes. .io is widely trusted in tech, especially for SaaS, developer tools and APIs, and short names are far easier to find than on .com.
No. Google treats .io as a generic domain, so it ranks worldwide just like .com.
The .io registry charges higher wholesale prices, so annual registration and renewal cost more than a typical .com.
Type your name above. We query the .io registry in real time and show a Register button for anything that's free.
.dev and .app for developer products, .ai for AI tools, and .co as a short alternative to .com.