UUID Inspector & Decoder

Paste any UUID-shaped string and see its version (1–8, NIL, or MAX), variant (RFC 4122, Microsoft legacy, NCS, or reserved future), and — for time-based versions (v1, v6, v7) — the embedded timestamp in unix milliseconds and human UTC. Also shown: canonical, Microsoft braced, URN, 32-char hex, and compact base64 forms. Pure client-side, no upload.

0 chars

Tip: accepts 32 hex chars, 8-4-4-4-12 with hyphens, the Microsoft braced form {xxxxxxxx-…}, and the URN form urn:uuid:…. Whitespace and case are ignored. Nothing is sent anywhere.

Try one — click any chip to load it
About UUID versions and variants
  • Version is a 4-bit field in the high nibble of byte 6 (the 7th byte). RFC 4122 defines v1 through v5; RFC 9562 (2024) supersedes it with v6 (reordered v1, sortable) and v7 (Unix-ms time-ordered), and adds v8 for custom layouts.
  • Variant is a variable-length prefix of byte 8 read MSB-first. The four valid prefixes are 0 (NCS), 10 (RFC 4122 / RFC 9562 — the modern standard), 110 (Microsoft legacy GUID), and 111 (reserved future).
  • v1 / v6 encode a 60-bit Gregorian timestamp (100-ns intervals since 1582-10-15) plus a 14-bit clock sequence and a 48-bit node id (often the host MAC, but v1 from modern systems uses a random node instead).
  • v7 encodes a 48-bit unix timestamp in milliseconds in the top 6 bytes — that's why v7 sorts chronologically in any database.
  • NIL (00000000-0000-0000-0000-000000000000) and MAX (ffffffff-…) are RFC 4122 §4.1.7 sentinels; they're the only two UUIDs with no version or variant in the usual sense.