GitHub Username Checker
Type a name and this asks GitHub's API whether a user or organization already has it, then checks the name is not one of the paths GitHub keeps for its own pages. GitHub usernames are 1 to 39 characters of letters, numbers and single hyphens, with no hyphen at the start or end. Users and organizations share one namespace, so an org name is taken for personal accounts too.
Free, no sign-in. Checks github.com/name plus .com, .dev, .io.
GitHub username rules
- 1 to 39 characters.
- Letters, numbers and hyphens. No underscores, dots or spaces.
- No hyphen at the start or end, and never two hyphens in a row.
- Case is ignored: Torvalds and torvalds are one account.
A name that breaks these is reported as not allowed without asking GitHub.
What taken and available mean on GitHub
Users and organizations share names
GitHub's /users/name lookup answers for both, so an organization holding a name blocks a personal account with it, and the other way round.
Some free-looking names are GitHub's own pages
Measured on 2026-10-28: the API returns 404 for about and settings because no account has them, yet github.com/about is a GitHub page and github.com/settings redirects. The checker loads the profile URL too and marks those as not allowed instead of available.
Deleted accounts free their names after 90 days
GitHub's documentation says a deleted account's username becomes available to anyone after 90 days. Until then it can 404 here and still be refused at signup.
The matching domain
A developer's name domain is the portfolio, the blog and the email address that outlives any employer. .dev is built for developers and forces HTTPS, .io is the long-time default for tools and side projects, and .com is what everyone else types.
GitHub username questions
How do I check if a GitHub username is available?
Type it in the box at the top of this page. domhaul asks GitHub's API whether a user or organization has it, then loads github.com/name to rule out names GitHub reserves for its own pages. No GitHub account or sign-in needed.
What characters can a GitHub username have?
Letters, numbers and single hyphens, up to 39 characters. It cannot start or end with a hyphen or contain two hyphens in a row. Underscores and dots are not allowed, which is why many people with an underscore handle elsewhere use a hyphen on GitHub.
Why is a name marked not allowed when no profile exists?
Because github.com/name is already one of GitHub's own pages, such as about or settings. No account has the name, so the API says it does not exist, but nobody can register it either.
Is a GitHub organization name the same as a username?
They share one namespace. If an organization is called acme, nobody can create a personal account called acme, and the checker reports it as taken.
When does a deleted GitHub account's username become available?
After 90 days, according to GitHub's own documentation. Until then the name can look free here, because no account has it, and still be refused when you try to sign up with it.
Check the name everywhere
Free checkers for Twitch usernames and Bluesky usernames, or all three at once. To check the handle matching your domain on all 11 platforms, X, Instagram, TikTok, YouTube, Facebook, LinkedIn, Reddit and Medium included, use social handle availability. Still choosing a name? Browse available domain name ideas by niche or price one you have in the domain value calculator.