Online Tool Store
UUID Validator
Check whether a UUID is correctly formatted, and see its version and variant decoded, with a random UUID generator to test with.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
How the UUID validator works
- Paste a UUID, or click "Generate a random UUID" to try one.
- The tool checks it against the standard 8-4-4-4-12 hexadecimal format.
- If valid, it also reports the UUID's version and variant, decoded from specific characters within it.
FAQ
What does the UUID "version" mean?
It indicates how the UUID was generated — version 4 (the most common) is randomly generated, version 1 is based on timestamp and MAC address, and other versions use different generation schemes. The version is encoded in one specific character of the UUID itself.
What is the "variant"?
It identifies which UUID layout standard the value follows — the vast majority of UUIDs you'll encounter use the RFC 4122 variant, which is what most UUID-generating libraries and databases produce by default.
What is a "Nil UUID"?
It's the special all-zeros UUID (00000000-0000-0000-0000-000000000000), sometimes used as a placeholder or "no value" marker rather than an actual generated identifier.
Is my UUID sent anywhere?
No. Validation happens instantly in your browser as you type — nothing is sent to Online Tool Store or any other server.
How we compare
| Feature | Online Tool Store | UUID Tools online validators | Regex in a script |
|---|---|---|---|
| Shows version and variant, not just valid/invalid | ✓ | Varies | Requires writing code |
| Instant, no button click | ✓ | Varies | ✓ |
| Can generate a random UUID to test | ✓ | Separate tool needed | Separate tool needed |
For an instant UUID check that also explains its version and variant, the Online Tool Store UUID Validator gives you more than a simple pass/fail.