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 7 of 20
#WebsitePageRankLinking sitesGlobal rankCompare
151coda.io8.002,5817,092Compare
152gupy.io8.002,6547,098Compare
153docusaurus.io7.991,2827,206Compare
154vaultproject.io7.991,3477,212Compare
155the7.io7.991,4787,220Compare
156frase.io7.992,4947,295Compare
157istio.io7.981,4927,458Compare
158traefik.io7.981,5737,470Compare
159codecov.io7.981,6547,474Compare
160hexo.io7.981,6367,476Compare
161shodan.io7.981,9957,495Compare
162subscribepage.io7.982,1117,510Compare
163snov.io7.982,5337,547Compare
164grsm.io7.982,6197,550Compare
165podman.io7.971,5817,665Compare
166strapi.io7.961,7547,782Compare
167pinecone.io7.962,2447,797Compare
168chef.io7.951,5367,892Compare
169getbee.io7.941,1618,005Compare
170stoplight.io7.941,2108,010Compare
171goldcast.io7.941,2738,012Compare
172ipaper.io7.941,4308,022Compare
173socialinsider.io7.932,1548,228Compare
174mailtrack.io7.933,0948,271Compare
175hackaday.io7.933,4628,283Compare

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.