.io

.io is the country-code top-level domain for the British Indian Ocean Territory. Unlike many country-code extensions, it is registered and used widely outside the territory. The official .IO registry allows registrations from anywhere and issues available names on a first-come, first-served basis.

The extension has developed a particularly strong association with technology. In computing, I/O is a standard abbreviation for input/output, so a short name ending in .io can feel natural for software companies, developer tools, infrastructure products, APIs, data platforms and technology startups. That technology meaning is a modern use of the letters rather than the reason the country code was created.

A .io domain can be attractive when the audience is comfortable with technology terminology and the brand benefits from a concise, technical identity. For a mainstream consumer business, however, some visitors may be less familiar with the extension or may assume a .com address, so the intended audience and how the domain will be communicated are worth considering.

Second-level .io registrations do not require the registrant to live in the British Indian Ocean Territory. Individual names can still be unavailable, reserved or affected by trademark and other legal rights, and registrants remain subject to the registry's policies and terms.