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 01a1984e-b2a7-7320-93ad-777a047cbfeb

Version 7 Unix Epoch time-based Sortable by time
01a1984eb2a7 unix_ts_ms
7 ver
320 rand_a
93ad777a047cbfeb var + rand_b
Version7 Unix Epoch time-based
VariantRFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)
Timestamp (UTC)2026-11-01T18:10:56.807Z
Unix: 1793556656807 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) 01a1984e-b2a7-7320-93ad-777a047cbfeb
Uppercase 01A1984E-B2A7-7320-93AD-777A047CBFEB
Microsoft GUID (braces) {01A1984E-B2A7-7320-93AD-777A047CBFEB}
URN urn:uuid:01a1984e-b2a7-7320-93ad-777a047cbfeb
32 hex digits 01a1984eb2a7732093ad777a047cbfeb
Base64 (RFC byte order) AaGYTrKncyCTrXd6BHy/6w==
128-bit integer (decimal) 2168276951356220320777687781491916779
.NET Guid.ToByteArray() (hex) 4e98a101a7b2207393ad777a047cbfeb
.NET Guid bytes (Base64) TpihAaeyIHOTrXd6BHy/6w==

API: /api/decode/01a1984e-b2a7-7320-93ad-777a047cbfeb

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.