UUID Inspector
Check whether a UUID is valid. It reports the version and variant, breaks the bits down field by field, and reads the creation time out of v1, v6 and v7 values. Paste many at once.
About UUID inspection
Any notation works
Uppercase, braces, the unhyphenated 32-character form, a urn:uuid: prefix, and surrounding whitespace are all normalized before validation. Paste multiple lines to check them at once — invalid lines are flagged with their line numbers.
Special UUIDs
RFC 9562 defines two special values. Neither follows the version or variant bit rules, so ordinary validation would reject them, yet both are valid per the specification.
- Nil
00000000-0000-0000-0000-000000000000 - Max
ffffffff-ffff-ffff-ffff-ffffffffffff
Versions that carry a timestamp
Only v1, v6 and v7 embed time. A v4 UUID is entirely random, so its creation moment cannot be recovered. v1 and v6 count 100-nanosecond intervals since 1582-10-15; v7 counts milliseconds since 1970-01-01.
v1 and v6 store the same timestamp in opposite order. v1 puts the low part first; v6 puts the high part first — which is the whole reason v6 exists. Only with the high part leading does plain string sorting come out in time order. That is also why the labels in the structure table swap places between the two versions.
Reference: RFC 9562 §5.1, §5.6, §5.7, §5.9, §5.10