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 01a1bfe0-351a-73e5-9430-b5fe6fa0f74a

Version 7 Unix Epoch time-based Sortable by time
01a1bfe0351a unix_ts_ms
7 ver
3e5 rand_a
9430b5fe6fa0f74a var + rand_b
Version7 Unix Epoch time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-11-09T10:35:04.346Z
Unix: 1794220504346 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) 01a1bfe0-351a-73e5-9430-b5fe6fa0f74a
Uppercase 01A1BFE0-351A-73E5-9430-B5FE6FA0F74A
Microsoft GUID (braces) {01A1BFE0-351A-73E5-9430-B5FE6FA0F74A}
URN urn:uuid:01a1bfe0-351a-73e5-9430-b5fe6fa0f74a
32 hex digits 01a1bfe0351a73e59430b5fe6fa0f74a
Base64 (RFC byte order) AaG/4DUac+WUMLX+b6D3Sg==
128-bit integer (decimal) 2169079493786408684329238558662522698
.NET Guid.ToByteArray() (hex) e0bfa1011a35e5739430b5fe6fa0f74a
.NET Guid bytes (Base64) 4L+hARo15XOUMLX+b6D3Sg==

API: /api/decode/01a1bfe0-351a-73e5-9430-b5fe6fa0f74a

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.