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 1f1cdb68-acca-6234-a33d-a54f1520b8b3

Version 6 Reordered Gregorian time-based Sortable by time
1f1cdb68 time_high
acca time_mid
6 ver
234 time_low
a33d var + clock_seq
a54f1520b8b3 node
Version6 Reordered Gregorian time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-10-22T01:18:52.1604660Z
Unix: 1792631932 s. Exact to 100 nanoseconds.
Clock sequence9021
Nodea5:4f:15:20:b8:b3 Random node ID (multicast bit set; not a real MAC address)

Version 6 is version 1 with the timestamp reordered (most significant bits first) so the UUIDs sort by creation time.

Formats

Standard (lowercase) 1f1cdb68-acca-6234-a33d-a54f1520b8b3
Uppercase 1F1CDB68-ACCA-6234-A33D-A54F1520B8B3
Microsoft GUID (braces) {1F1CDB68-ACCA-6234-A33D-A54F1520B8B3}
URN urn:uuid:1f1cdb68-acca-6234-a33d-a54f1520b8b3
32 hex digits 1f1cdb68acca6234a33da54f1520b8b3
Base64 (RFC byte order) HxzbaKzKYjSjPaVPFSC4sw==
128-bit integer (decimal) 41355902322279556900673086475429001395
.NET Guid.ToByteArray() (hex) 68db1c1fcaac3462a33da54f1520b8b3
.NET Guid bytes (Base64) aNscH8qsNGKjPaVPFSC4sw==

API: /api/decode/1f1cdb68-acca-6234-a33d-a54f1520b8b3

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.