UUID Validator & Inspector
Paste a UUID to check whether it is well-formed, then decode its version and variant. Version-1 UUIDs reveal the timestamp baked into them.
UUID
Try
Valid UUIDThe string matches the canonical 8-4-4-4-12 hexadecimal format.
Normalized
550e8400-e29b-41d4-a716-446655440000Versionv4
Random, with 122 bits drawn from a random or pseudo-random source.
VariantRFC 4122
The standard variant used by RFC 4122 and RFC 9562 UUIDs (bits 10).
Version reference
- v1Time-based, using a 60-bit timestamp and the node's MAC address.
- v2DCE Security, embedding a POSIX UID or GID in place of part of the clock.
- v3Name-based, hashing a namespace and name with MD5.
- v4Random, with 122 bits drawn from a random or pseudo-random source.
- v5Name-based, hashing a namespace and name with SHA-1.
- v6Reordered time-based, a field-reordered v1 that sorts by creation time.
- v7Unix epoch time-based, a 48-bit millisecond timestamp plus random bits.
- v8Custom or experimental, with a vendor-defined layout.
Variant reference
- NCSReserved for NCS backward compatibility (leading bit 0).
- RFC 4122The standard variant used by RFC 4122 and RFC 9562 UUIDs (bits 10).
- MicrosoftReserved for Microsoft Corporation GUIDs (bits 110).
- FutureReserved for future definition (bits 111).
About UUIDs
A UUID is a 128-bit identifier written as 32 hexadecimal digits in five hyphen-separated groups (8-4-4-4-12). The version nibble and the variant bits encode how it was generated. This inspector runs entirely in your browser; nothing is uploaded.