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 01a1ad69-252d-70a9-86a9-8cc6b73d0cfc

Version 7 Unix Epoch time-based Sortable by time
01a1ad69252d unix_ts_ms
7 ver
0a9 rand_a
86a98cc6b73d0cfc var + rand_b
Version7 Unix Epoch time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-11-05T20:31:51.597Z
Unix: 1793910711597 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) 01a1ad69-252d-70a9-86a9-8cc6b73d0cfc
Uppercase 01A1AD69-252D-70A9-86A9-8CC6B73D0CFC
Microsoft GUID (braces) {01A1AD69-252D-70A9-86A9-8CC6B73D0CFC}
URN urn:uuid:01a1ad69-252d-70a9-86a9-8cc6b73d0cfc
32 hex digits 01a1ad69252d70a986a98cc6b73d0cfc
Base64 (RFC byte order) AaGtaSUtcKmGqYzGtz0M/A==
128-bit integer (decimal) 2168704977333397915357704535980969212
.NET Guid.ToByteArray() (hex) 69ada1012d25a97086a98cc6b73d0cfc
.NET Guid bytes (Base64) aa2hAS0lqXCGqYzGtz0M/A==

API: /api/decode/01a1ad69-252d-70a9-86a9-8cc6b73d0cfc

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.