Why does a platform show couldn't verify?

A login wall, challenge page, rate limit, timeout or missing profile marker can prevent a reliable answer. TikTok, Threads and Pinterest always need a manual check here. Instagram without a profile marker and a generic Twitch page also stay unverified. Open the profile link by hand; the platform makes the final call.

Does checking reserve the name?

No. Available means the service returned an explicit not-found signal, not that the name is reserved or guaranteed claimable. A platform or registry may restrict a name, and someone else can claim it. Confirm with that service before choosing your name.

Which handle characters can I check?

Enter 1–30 lowercase letters, digits, dots, underscores or hyphens. Surrounding spaces and one leading @ are removed. GitHub allows letters, digits and single internal hyphens, with no dots or underscores. Domain labels allow letters, digits and internal hyphens.

How do the other platform rules differ?

YouTube needs 3–30 characters with no dot, underscore or hyphen at either end. X allows letters, digits and underscores up to 15 characters; signup may impose a minimum. New .bsky.social names use 3–18 letters, digits or internal hyphens. Twitch uses 4–25 letters, digits or underscores. Instagram and Threads exclude hyphens. TikTok excludes hyphens and a final dot. Pinterest uses 3–30 letters, digits or underscores and needs at least one letter. The service's signup rules are final.

What do the domain results mean?

A successful RDAP registration response means taken; an authoritative registry not-found response means available in the registration data. If RDAP cannot locate a registry service, the result is couldn't verify. A domain can be registered without a working website. A registry or registrar can still reserve or restrict an unregistered name.

No account, saved search or database record is created. Results are held temporarily in server memory for 10 minutes. Answers with an inconclusive automated check expire after 1 minute. There are at most 100 cached handles per process. Handles are not included in the tool's application logs.

Yes. GET /api/tools/username-check?handle=yourname returns JSON. Send Accept: text/markdown for Markdown. No key is needed. Each caller has 30 calls a minute and 300 a day. One handle is checked per call, with platforms checked in parallel, 5 seconds per platform and four scans per server process. Responses include checkedAt, cached and ageSeconds.

Free username availability checker for creators

How to check a username

Enter one handle. Type your handle, with or without a leading @, and choose Check username.
Review each platform. Look for taken, available or couldn't verify. A handle that breaks a platform's rules is marked not allowed there.
Confirm and claim your name. Open the profile links to confirm on each platform, then try the same name on BioFlow. Checking does not reserve a name.

What it checks

Profile signals from YouTube, X, GitHub, Bluesky, Twitch and Instagram
Manual profile links for TikTok, Threads and Pinterest
Registration checks for .com, .net, .org and .app domains through RDAP
A free JSON or Markdown API with no account or key

How to read your results

Taken means a profile or domain registration returned a positive found signal. Available means the service returned an explicit not-found signal. Neither result reserves a name: the platform makes the final call.

Login walls, browser challenges, rate limits and timeouts show couldn't verify. So do missing profile markers. Instagram without a marker and a generic Twitch page stay unverified. TikTok, Threads and Pinterest always need a manual check here. Every result includes a link to open by hand.

Use a consistent name across your profiles and your link-in-bio page. Confirm the name with each service before you build a brand around it.

Use the free API

Send one handle as the handle query parameter. Add Accept: text/markdown for a Markdown answer. No key or account is needed.

GET /api/tools/username-check?handle=yourname

API errors

400 invalid_handle: supply one valid handle of 1–30 characters.
429 rate_limited: wait for Retry-After; the allowance is 30 calls a minute and 300 a day.
503 busy: all four scan slots are in use; try again after 5 seconds.

Username availability checker