Username OSINT Checker — GitHub, GitLab, Docker Hub, Keybase, Hacker News

Find out whether a username is taken across five developer-facing platforms in a single call. Each platform is queried through its own public API — no login, no scraping, no anti-bot circumvention.

Duplicates are checked once and charged once

A username repeated in the same batch is checked once. Every submitted line still gets its own output row, in your original order, so the result joins straight back onto your list — the repeat carries is_duplicate: true and is not charged.

Here that matters more than on a pure-computation tool: every username costs five outbound HTTP calls, one per platform. Not repeating them saves your run time and avoids sending pointless traffic to GitHub, GitLab, Docker Hub, Keybase and Hacker News.

Capitalisation is kept, deliberately. GitHub and GitLab treat usernames case-insensitively, but Hacker News does not — folding case here would merge two names that are genuinely different on at least one of the five platforms. Torvalds and torvalds are therefore checked separately.

The run also writes a SUMMARY record to the key-value store: how many usernames were submitted, how many were unique, how many duplicates were skipped and how many HTTP calls that saved.

What it does

For each username, five checks run in parallel:

Platform	What is checked
GitHub	whether the user account exists
GitLab	whether the username is in use
Docker Hub	whether the account exists
Keybase	whether the identity is registered
Hacker News	whether the user profile exists

A platform that times out or errors is reported as unknown, never as "not found". That distinction matters: for name-availability research, silently turning an outage into "free to take" is the one error that actually costs you something.

Usernames are format-checked first — letters, digits, underscore, dot and hyphen only.

Use cases

• Brand and project naming — before committing to a name, see where the handle is already taken across the platforms developers actually use.
• OSINT and due diligence — map a known handle's presence across developer platforms from public endpoints only.
• Account-handle cleanup — bulk-check a list of handles your organisation believes it owns.

Input

{ "usernames": ["octocat", "torvalds"] }

Output (one row per username)

{
  "username": "octocat",
  "checked_at": "2026-08-27T05:42:48.242Z",
  "verdict": "checked",
  "github_found": true,
  "gitlab_found": false,
  "dockerhub_found": false,
  "keybase_found": true,
  "hackernews_found": true,
  "found_count": 3,
  "unknown_count": 0
}

Pricing

Pay-per-event: $0.0152 per username checked, charged once per username once the five platform checks have completed — a single price covering all five, whatever each one returns.

Limitations — read this before you buy

• Five platforms only, all developer-facing: GitHub, GitLab, Docker Hub, Keybase, Hacker News. There is deliberately no social-network coverage here — those platforms' terms of service forbid this kind of automated lookup, and building on top of that would put your account at risk as much as ours.
• "Not found" is not a legal availability guarantee. A free handle can still be reserved, trademarked, or held by a suspended account.
• unknown means unknown. A platform that is down or rate-limiting returns unknown, and it is never collapsed into "not found".
• Only public endpoints are used, so only public profiles are visible.

FAQ

Why is one platform unknown while the others answered? That platform timed out or rate-limited the request. Re-running the username usually resolves it.

Does this check social networks? No, by design — see Limitations.

Related Actors

Part of the same family of small, single-purpose checkers on this account — each does one thing, priced per item checked:

• IBAN Validator & Formatter — ISO 13616 length + mod-97 checksum, fully offline.
• Card Number Validator (Luhn) — Luhn checksum and card-network detection, output is masked.
• Barcode Check-Digit Validator — EAN-13, EAN-8 and UPC-A check digits.
• EU VAT Number Checker — official VIES lookup.
• Email Address Validator — syntax, domain and MX checks.
• Password Strength Checker — entropy scoring, never returns the password.
• Cron Expression Validator — plain-English description and next run times.
• French E-Invoice Partner Resolver — SIRET / SIREN / VAT resolution.