UUID Version Detector

A UUID Version Detector validates UUID format and identifies which version (1-5 or NIL) a UUID belongs to. Each version has a different structure and generation method. The version is encoded in the 13th character (first digit of the third group).

This tool parses each section of the UUID with color coding, extracts embedded information (like timestamps in v1), and shows the variant (RFC 4122, Microsoft, etc.). It supports batch analysis — paste many UUIDs, one per line, to analyze them all at once.

A UUID is 128 bits displayed as 32 hexadecimal digits in five groups: 8-4-4-4-12. The version nibble is at position 13 (0-indexed), and the variant nibble is at position 17. Version 4 (random) is the most common; you'll see '4' in the version position. Version 1 has a timestamp in the first 48 bits; version 3 and 5 have hash-derived values in the non-version portions.

The NIL UUID (00000000-0000-0000-0000-000000000000) is used to represent a null or uninitialized value. This tool detects and labels it separately.

Use this tool when debugging UUID-related code, verifying that generated UUIDs match expected versions, auditing databases for UUID version distribution, or learning how different UUID versions encode data. It's also useful when integrating with systems that expect specific UUID versions (e.g., some databases prefer v7 for time-ordered UUIDs) and you need to verify compatibility.