UUIDTools.com

UUID Validator & Decoder

Paste a UUID or GUID to check it and see what is inside: version, variant, timestamp and more.

Accepts hyphenated, 32 hex digits, {braces}, urn:uuid:, any case. Try a fresh v7.

Valid 01a19650-85d6-70e2-91ab-f95480263f71

Version 7 Unix Epoch time-based Sortable by time
01a1965085d6 unix_ts_ms
7 ver
0e2 rand_a
91abf95480263f71 var + rand_b
Version7 Unix Epoch time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-11-01T08:53:41.974Z
Unix: 1793523221974 ms. Milliseconds.

Version 7 UUIDs start with a 48-bit Unix timestamp in milliseconds followed by random bits, so they sort by creation time.

Formats

Standard (lowercase) 01a19650-85d6-70e2-91ab-f95480263f71
Uppercase 01A19650-85D6-70E2-91AB-F95480263F71
Microsoft GUID (braces) {01A19650-85D6-70E2-91AB-F95480263F71}
URN urn:uuid:01a19650-85d6-70e2-91ab-f95480263f71
32 hex digits 01a1965085d670e291abf95480263f71
Base64 (RFC byte order) AaGWUIXWcOKRq/lUgCY/cQ==
128-bit integer (decimal) 2168236531123321528951240880738942833
.NET Guid.ToByteArray() (hex) 5096a101d685e27091abf95480263f71
.NET Guid bytes (Base64) UJahAdaF4nCRq/lUgCY/cQ==

API: /api/decode/01a19650-85d6-70e2-91ab-f95480263f71

How to decode a UUID

Every RFC 9562 UUID stores its version in the 13th hex digit and its variant in the top bits of the 17th digit:

xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx
             M = version (1-8)   N = variant (8, 9, a, b = RFC 9562)
Version digitMeaningContains a timestamp?
1Gregorian time-basedYes (100 ns since 1582)
2DCE SecurityPartial
3Name-based, MD5No
4RandomNo
5Name-based, SHA-1No
6Reordered Gregorian timeYes (100 ns since 1582)
7Unix Epoch timeYes (ms since 1970)
8CustomOnly if your format has one

Variant digit

BinaryHex digitVariant
0xxx0 - 7Reserved, NCS backward compatibility
10xx8 - bRFC 9562 (the standard variant)
110xc - dReserved, Microsoft backward compatibility
111xe - fReserved for future definition

The decoder never throws on odd input: unknown versions, legacy variants and the special nil (00000000-…) and max (ffffffff-…) UUIDs all produce a readable result.

Learn more in UUID versions explained.