Does .os exist?
No. No — .os is not a TLD. Operating-system branding never got its own extension.
The full story
Despite how natural 'something.os' looks in tech branding, no .os TLD has ever been applied for successfully or delegated. Projects wanting the vibe typically use domain hacks on existing TLDs (like .so — Somalia's ccTLD, one letter away) or country codes that spell it.
What to use instead
.so — Sharp and word-hacky (notion.sh — The shell-script TLD.dev — Best value in domains for anything developer-facing
Wondering about another extension? Every real TLD is in the directory.
This answer is generated from the live IANA root zone list, not from vibes. If the DNS changes, this page changes.