A UUID validator confirms that a string is a well-formed universally unique identifier and tells you what kind it is. This tool checks the format, then decodes the version and variant bits and, for time-based UUIDs, the embedded creation time — all in your browser.
Paste a value above and the result updates instantly. Nothing is sent to a server, so it is safe to check identifiers from production systems.
What makes a UUID valid?
A canonical UUID is 32 hexadecimal digits arranged as 8-4-4-4-12 and separated by hyphens, for example 123e4567-e89b-12d3-a456-426614174000. This validator also accepts inputs wrapped in braces or prefixed with urn:uuid:, and 32-digit forms without hyphens, normalising them before checking.
Beyond the shape of the string, a UUID encodes a version (which generation scheme produced it) and a variant (which layout standard it follows). The validator extracts both so you can confirm a value is, say, a genuine RFC 9562 v7 identifier rather than an arbitrary hex string.
Reading the results
Version is the digit that identifies how the UUID was created: 1 and 6 are time-based, 4 is random, 5 and 3 are name-based, and 7 is the modern time-ordered scheme. The variant indicates the bit layout; almost every UUID you encounter is the "RFC 4122 / RFC 9562" variant.
For version 1 and version 7 UUIDs the validator also decodes the embedded timestamp, showing when the identifier was generated. The all-zero Nil UUID and the all-ones Max UUID are flagged as the special reserved values they are.
Frequently asked questions
- How do I know if a UUID is valid?
- A valid UUID has 32 hexadecimal digits in the 8-4-4-4-12 pattern. Paste it above and the validator confirms the format and shows its version and variant.
- Can this tool tell me which UUID version I have?
- Yes. It reads the version digit and reports whether the UUID is v1, v3, v4, v5, v6, v7, or a special Nil/Max value.
- Is my UUID sent anywhere when I validate it?
- No. All validation and decoding happens locally in your browser, so it is safe to check identifiers from private systems.