GitHub Username Checker
A GitHub username is the namespace for your profile and every repository you own, as in github.com/name/repo. Renaming later breaks some links, so many developers check carefully first. Type a name below to look it up through GitHub's public API.
GitHub username rules
| Allowed characters | Alphanumeric characters and single hyphens only. |
|---|---|
| Hyphens | Cannot start or end with a hyphen, and no two hyphens in a row. |
| Length | GitHub's docs describe a 39-character limit for usernames. |
| Inactive names | GitHub does not release, transfer or reclaim usernames because they look inactive; only valid trademark complaints are reviewed. |
| Old name after a rename | Your old username becomes available for anyone to claim. |
Sources: GitHub Docs: username considerations, GitHub Docs: username policy, GitHub Docs: changing your username, GitHub Docs: about username changes. Last reviewed 2026-10-13. Platforms change their rules; the linked help pages are the final word.
How to check a GitHub username
- Enter the name using only letters, numbers and single hyphens; underscores and periods are not valid on github.com.
- We query api.github.com/users/<name>. The anonymous API allows only a small number of requests per hour from one address, so heavy use can return "Blocked" until the limit resets.
- Manual check: visit github.com/<name>. A 404 page means no user or organization currently owns it.
- Organizations share the same namespace as users, so a name can be taken by a company even if no person uses it.
GitHub username taken? What you can do
- GitHub recommends choosing a variation with numbers, hyphens or a different spelling, for example mia-dev or miacodes.
- Inactive accounts are not released. GitHub's policy says it does not reclaim names on the basis that they appear unused.
- If the name matches your registered trademark, file a trademark complaint; that is the only kind of request GitHub reviews for a release.
- Do not buy a username. GitHub prohibits selling or soliciting payment for account names and may suspend accounts that try.
How to change your GitHub username
- Click your profile picture, then Settings.
- In the left sidebar, click Account.
- Under Change username, click Change username and read the warnings.
- Type the new name and click Change my username if it is available.
Reserved and restricted names
GitHub prohibits name squatting: account names may not be reserved or held inactively for future use, and squatted names may be removed or renamed without notice. Valid trademark complaints are the only route to a release of a claimed name.
Tips
- After a rename, github.com/oldname returns a 404, and someone else can claim it. Update your LinkedIn, résumé and package registry links.
- Repository web and git URLs redirect automatically, but a new owner of your old name can break those redirects by creating a repo with the same name.
- Popular Actions or heavily cloned repositories cause GitHub to retire the old owner and repo name combination permanently.
Frequently asked questions
Can I use an underscore in a GitHub username?
No. Personal GitHub usernames allow only letters, numbers and single hyphens.
Will GitHub give me an inactive username?
No. GitHub's username policy says it does not release names because they appear inactive; only valid trademark complaints are reviewed.
Do my repositories break if I change my GitHub username?
Most repository references redirect automatically, but your old profile URL returns a 404 and @mentions of the old name do not follow you.
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WhatsMyName Apps is an independent tool, not affiliated with or endorsed by GitHub, the WhatsMyName project, Sherlock or Maigret. Results are leads to verify.