The top .io websites by PageRank belong to developers and software companies. GitHub Pages, documentation hosts and open-source projects lead, followed by SaaS tools for analytics, forms and privacy notices.

The .io ending is the country code of the British Indian Ocean Territory, but tech startups adopted it because "IO" reads like input/output.

500 sites · page 13 of 20
#WebsitePageRankLinking sitesGlobal rankCompare
301fury.io7.5659215,398Compare
302ebpf.io7.5670515,408Compare
303coveralls.io7.5687215,417Compare
304harness.io7.561,14815,438Compare
305neovim.io7.561,27015,447Compare
306soup.io7.562,17615,527Compare
307hasura.io7.5476215,733Compare
308pivotal.io7.5496315,745Compare
309itnext.io7.541,14515,762Compare
310instana.io7.5348515,887Compare
311zerkalo.io7.5350915,891Compare
312livekit.io7.5360915,896Compare
313systemd.io7.5364915,897Compare
314artifacthub.io7.5386415,919Compare
315api-sports.io7.5387015,920Compare
316karte.io7.531,01415,937Compare
317avada.io7.531,14915,952Compare
318accessibilityinsights.io7.5264616,120Compare
319tray.io7.5268416,123Compare
320document360.io7.5277516,132Compare
321akka.io7.5278216,134Compare
322dbeaver.io7.5193816,330Compare
323zaiko.io7.511,68116,409Compare
324kissmetrics.io7.5095316,517Compare
325umbraco.io7.501,18116,541Compare

Data: Open PageRank, data file October 2026. Domain data derived from Common Crawl. Not Google's own PageRank.

Why the top .io websites are widgets and hosts

Some .io services sit inside other websites: a review widget, a cookie banner or a status page. Every site that embeds one links back to it, so the score climbs fast even when few people visit the service itself.

Hosting domains like GitHub Pages also collect links for every project they host. That is why they rank above many famous apps.

Browse the top .io websites to find tools your own site may already use, and compare them in the checker.

Frequently asked questions

What does .io stand for?

It is the country code of the British Indian Ocean Territory. Tech companies like it because IO also means input/output.

Why is github.io at the top?

GitHub Pages hosts millions of project sites on github.io, and the links to all of them count for the whole domain.

Is a .io domain good for SEO?

Google treats .io like a generic ending, not a country site. The ending itself does not raise your score; links do.