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 01a18a2e-cc66-71b4-a95a-c850f6076059

Version 7 Unix Epoch time-based Sortable by time
01a18a2ecc66 unix_ts_ms
7 ver
1b4 rand_a
a95ac850f6076059 var + rand_b
Version7 Unix Epoch time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-10-30T00:21:25.222Z
Unix: 1793319685222 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) 01a18a2e-cc66-71b4-a95a-c850f6076059
Uppercase 01A18A2E-CC66-71B4-A95A-C850F6076059
Microsoft GUID (braces) {01A18A2E-CC66-71B4-A95A-C850F6076059}
URN urn:uuid:01a18a2e-cc66-71b4-a95a-c850f6076059
32 hex digits 01a18a2ecc6671b4a95ac850f6076059
Base64 (RFC byte order) AaGKLsxmcbSpWshQ9gdgWQ==
128-bit integer (decimal) 2167990470288592104960121116652167257
.NET Guid.ToByteArray() (hex) 2e8aa10166ccb471a95ac850f6076059
.NET Guid bytes (Base64) LoqhAWbMtHGpWshQ9gdgWQ==

API: /api/decode/01a18a2e-cc66-71b4-a95a-c850f6076059

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.