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 01a1a08a-9e12-722b-9757-f7018b0d6622

Version 7 Unix Epoch time-based Sortable by time
01a1a08a9e12 unix_ts_ms
7 ver
22b rand_a
9757f7018b0d6622 var + rand_b
Version7 Unix Epoch time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-11-03T08:33:21.426Z
Unix: 1793694801426 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) 01a1a08a-9e12-722b-9757-f7018b0d6622
Uppercase 01A1A08A-9E12-722B-9757-F7018B0D6622
Microsoft GUID (braces) {01A1A08A-9E12-722B-9757-F7018B0D6622}
URN urn:uuid:01a1a08a-9e12-722b-9757-f7018b0d6622
32 hex digits 01a1a08a9e12722b9757f7018b0d6622
Base64 (RFC byte order) AaGgip4SciuXV/cBiw1mIg==
128-bit integer (decimal) 2168443957952965727263719539981772322
.NET Guid.ToByteArray() (hex) 8aa0a101129e2b729757f7018b0d6622
.NET Guid bytes (Base64) iqChARKeK3KXV/cBiw1mIg==

API: /api/decode/01a1a08a-9e12-722b-9757-f7018b0d6622

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.