What is .io?

The .io domain is technically the country code TLD for the British Indian Ocean Territory, but it has been adopted almost entirely by the tech industry. In computing, I/O stands for "Input/Output," making .io a natural fit for technology companies, APIs, developer tools, and SaaS products in the world of domains.

A Brief History

The .io domain was delegated in 1997 to the Internet Computer Bureau. For years it was relatively obscure until the tech startup boom of the 2010s discovered its I/O connection. Companies like GitHub (git.io), Socket.io, and countless Y Combinator startups popularized .io as the tech domain of choice.

Why Choose .io?

  • Tech credibility — .io is instantly recognized in the tech community as a startup/developer domain.
  • I/O meaning — Input/Output resonates with APIs, data platforms, and software products.
  • Short and clean — Two characters, looks great in URLs and branding.
  • Availability — Better name availability than .com for tech-related terms.

Who Uses .io?

Tech startups, developer tools, API platforms, cryptocurrency projects, and SaaS companies. Notable .io domains include draw.io, socket.io, and hundreds of well-funded startups.

Did You Know?

  • As of 2026, over 2.5 million .io domains are registered.
  • .io domains are significantly more expensive than .com — typically $30-50 per year for new registrations.
  • There is ongoing debate about .io's future since the British Indian Ocean Territory may be transferred to Mauritius, potentially affecting the TLD's governance.
  • Google treats .io as a generic TLD for search purposes, not as a country code.

Registration & Pricing

.io domains typically cost $30-50 per year — a premium over .com, but standard for tech-focused TLDs. DomainWorld offers .io registration — you can get a domain up and running in minutes.

The Future of .io

The potential sovereignty change for the British Indian Ocean Territory creates some uncertainty, but .io's massive adoption in the tech world makes it unlikely to disappear. In the world of domains, .io has earned its place as the tech TLD.