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 01a1bfa7-4412-7000-8a20-a196d609bbaf

Version 7 Unix Epoch time-based Sortable by time
01a1bfa74412 unix_ts_ms
7 ver
000 rand_a
8a20a196d609bbaf var + rand_b
Version7 Unix Epoch time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-11-09T09:32:52.626Z
Unix: 1794216772626 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) 01a1bfa7-4412-7000-8a20-a196d609bbaf
Uppercase 01A1BFA7-4412-7000-8A20-A196D609BBAF
Microsoft GUID (braces) {01A1BFA7-4412-7000-8A20-A196D609BBAF}
URN urn:uuid:01a1bfa7-4412-7000-8a20-a196d609bbaf
32 hex digits 01a1bfa7441270008a20a196d609bbaf
Base64 (RFC byte order) AaG/p0QScACKIKGW1gm7rw==
128-bit integer (decimal) 2169074982413730719896311260510796719
.NET Guid.ToByteArray() (hex) a7bfa101124400708a20a196d609bbaf
.NET Guid bytes (Base64) p7+hARJEAHCKIKGW1gm7rw==

API: /api/decode/01a1bfa7-4412-7000-8a20-a196d609bbaf

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.