developer · Checked at the edge
Is this Docker Hub username free?
Check any Docker Hub username against the platform itself, asked from the beat.rip edge. Beat.rip says taken, likely free or exactly why it cannot tell.
Opens Beat.rip with this platform selected; add more there.
- characters
- 4–30
- how it is checked
- Edge
- best free answer
- Likely free
Docker Hub username rules
- Length
- 4 to 30 characters
- Characters
- Lowercase letters, digits, underscores and hyphens. No capitals: the charset is lowercase only. Beat.rip lowercases what you type, so “Name” is checked as “name”.
Beat.rip checks these rules on your device before any request. A username that breaks them is marked invalid, never available, and no request is sent for it.
How Beat.rip checks Docker Hub
The beat.rip edge asks registry.hub.docker.com directly, and nobody in between. Users API on registry.hub.docker.com: 200 with the user, a 308 to /v2/orgs/{name} for an organisation (one namespace), 404 "User not found" for neither. hub.docker.com serves the same API and is the fallback; it answers 429 to Cloudflare’s egress even for one request (measured live 2026-10-29).
Requests are paced to at most 2 requests at a time, 200 ms apart, identify themselves as beat.rip, and each answer is cached for seconds to minutes, so a busy minute never hammers the platform.
Every result row links to https://hub.docker.com/u/name, with your name in place of “name”, so you can confirm by hand.
What each answer means on Docker Hub
- Taken
The platform’s own endpoint returned an account for the username.
- Likely free
No account at Docker Hub’s own endpoint. Likely free, but a name can still be reserved, suspended or held.
- Unknown
The platform refused, rate-limited or answered something unrecognised. The row says which and links to the profile.
- Invalid
The username breaks one of the rules above, so nothing was asked.
Questions about Docker Hub usernames
How long can a username be on Docker Hub?
Between 4 and 30 characters.
Which characters can a username use on Docker Hub?
Only lowercase letters, digits, underscores and hyphens. No capitals: the charset is lowercase only. Beat.rip lowercases what you type, so “Name” is checked as “name”.
Can Beat.rip tell whether a username is free on Docker Hub?
It can say “likely free” when Docker Hub’s own endpoint has no such account. A name can still be reserved, suspended or held, so Beat.rip never calls it available.
Does checking a username on Docker Hub reserve it?
No. Beat.rip cannot sign up on your behalf; claim the username on Docker Hub itself. Availability changes by the minute.