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TNToolsNexus

UUID generator

Generate 1–100 cryptographically random version-4 UUIDs — uppercase and no-hyphen options, copy all in one click. Local, private.

UUIDs are generated on your device with your browser's crypto — nothing is requested from a server.

Generate 1 to 100 version-4 UUIDs — cryptographically random via your browser’s own crypto.randomUUID() — with uppercase and no-hyphen variants and one-click copy-all.

How to generate UUIDs

  1. Set how many you need (1–100) — a fresh batch appears immediately.
  2. Toggle Uppercase or Keep hyphens to match your system’s convention.
  3. Copy all — one UUID per line, paste-ready for code, configs, or spreadsheets.

Where the randomness comes from

These aren’t Math.random() UUIDs. crypto.randomUUID() draws from the same CSPRNG your browser uses for TLS, seeded by the operating system — which is what makes v4 UUIDs safe to treat as globally unique without coordination. The format is fixed by RFC 4122/9562: 32 hex digits, the 13th always 4 (version), the 17th one of 8/9/a/b (variant). Everything else is 122 bits of noise.

Formats systems actually ask for

Standard lowercase-with-hyphens is what JSON APIs, Postgres uuid columns, and most languages emit. Uppercase matches Windows registry entries and many .NET codebases. No hyphens is the 32-character compact form some databases and URL designs prefer — same value, fixed positions, losslessly convertible back. Batch generation exists because IDs rarely travel alone: seeding test data, keying spreadsheet rows, pre-allocating identifiers for a migration. (Need a content fingerprint rather than a random ID? That’s a hash, not a UUID.)

Private by design

Generation happens on your device — nothing is fetched, transmitted, or logged, which also means no server ever knew the IDs now keying your data.

Last updated:

Frequently asked questions

What version are these UUIDs?
Version 4 — fully random except the six version/variant bits, generated by your browser's crypto.randomUUID(), which draws from the operating system's cryptographic random source. That's the version you want for IDs unless a spec explicitly demands time-ordered v7.
Can two generated UUIDs collide?
Theoretically; practically, no. With 122 random bits you'd need to generate about 2.7 quintillion UUIDs for a 50% chance of a single collision. Systems worldwide treat v4 UUIDs as unique without checking.
UUID or GUID — is there a difference?
Same 128-bit thing: GUID is Microsoft's historical name, UUID the standard's (RFC 4122/9562). Windows ecosystems often write them uppercase — the Uppercase option here matches that convention.
Why would I remove the hyphens?
Some databases, URL schemes, and legacy systems store the 32 hex characters raw. The no-hyphen option gives you that compact form; anything standards-compliant can re-insert hyphens because the positions are fixed.
Are these UUIDs sent from a server or logged?
No — they're generated on your device and never transmitted, so nobody else has ever seen them.

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