UUID Validator
Validate UUID format and detect the version. Paste one or many UUIDs (one per line) for bulk validation.
About UUID Validator
This tool checks whether a string is a correctly formatted UUID and identifies which version (v1–v8) it is. It also detects the variant (RFC 4122 standard vs others), flags the nil UUID (all zeros), and handles both uppercase and lowercase UUIDs with or without hyphens.
UUID Structure
A standard UUID has the format xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx where M is the version digit (1–8) and N encodes the variant (8, 9, a, or b for RFC 4122).
FAQ
The nil UUID is a special UUID where all 128 bits are zero: 00000000-0000-0000-0000-000000000000. It is a valid UUID but semantically represents "no UUID" — similar to null or zero.
The 32-character hex string without hyphens (e.g. 550e8400e29b41d4a716446655440000) is often used as a compact UUID representation. This tool accepts both formats.
The variant bits (bits 64–65) define the UUID layout. The RFC 4122 standard requires variant "10xx" — encoded as hex 8, 9, a, or b. Most UUIDs you encounter will be RFC 4122 compliant.