UUID Validator & Decoder: Version, Variant, Timestamp

Valid 01a1abe1-fa58-7071-af7e-48da03f0c15b

Version 7 Unix Epoch time-based Sortable by time

01a1abe1fa58 unix_ts_ms

7 ver

071 rand_a

af7e48da03f0c15b var + rand_b

Version	7 Unix Epoch time-based
Variant	RFC 9562 (formerly RFC 4122 / DCE 1.1) (bits `10`)
Timestamp (UTC)	`2026-11-05T13:24:36.056Z` Unix: 1793885076056 ms. Milliseconds.

Version

7 Unix Epoch time-based

Variant

RFC 9562 (formerly RFC 4122 / DCE 1.1) (bits 10)

Timestamp (UTC)

2026-11-05T13:24:36.056Z
Unix: 1793885076056 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)	`01a1abe1-fa58-7071-af7e-48da03f0c15b`
Uppercase	`01A1ABE1-FA58-7071-AF7E-48DA03F0C15B`
Microsoft GUID (braces)	`{01A1ABE1-FA58-7071-AF7E-48DA03F0C15B}`
URN	`urn:uuid:01a1abe1-fa58-7071-af7e-48da03f0c15b`
32 hex digits	`01a1abe1fa587071af7e48da03f0c15b`
Base64 (RFC byte order)	`AaGr4fpYcHGvfkjaA/DBWw==`
128-bit integer (decimal)	`2168673985865982195851811679565300059`
.NET Guid.ToByteArray() (hex)	`e1aba10158fa7170af7e48da03f0c15b`
.NET Guid bytes (Base64)	`4auhAVj6cXCvfkjaA/DBWw==`

Standard (lowercase)

01a1abe1-fa58-7071-af7e-48da03f0c15b

Uppercase

01A1ABE1-FA58-7071-AF7E-48DA03F0C15B

Microsoft GUID (braces)

{01A1ABE1-FA58-7071-AF7E-48DA03F0C15B}

URN

urn:uuid:01a1abe1-fa58-7071-af7e-48da03f0c15b

32 hex digits

01a1abe1fa587071af7e48da03f0c15b

Base64 (RFC byte order)

AaGr4fpYcHGvfkjaA/DBWw==

128-bit integer (decimal)

2168673985865982195851811679565300059

.NET Guid.ToByteArray() (hex)

e1aba10158fa7170af7e48da03f0c15b

.NET Guid bytes (Base64)

4auhAVj6cXCvfkjaA/DBWw==

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 digit	Meaning	Contains a timestamp?
1	Gregorian time-based	Yes (100 ns since 1582)
2	DCE Security	Partial
3	Name-based, MD5	No
4	Random	No
5	Name-based, SHA-1	No
6	Reordered Gregorian time	Yes (100 ns since 1582)
7	Unix Epoch time	Yes (ms since 1970)
8	Custom	Only if your format has one

Variant digit

Binary	Hex digit	Variant
`0xxx`	0 - 7	Reserved, NCS backward compatibility
`10xx`	8 - b	RFC 9562 (the standard variant)
`110x`	c - d	Reserved, Microsoft backward compatibility
`111x`	e - f	Reserved 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.

UUID Validator & Decoder

Valid 01a1abe1-fa58-7071-af7e-48da03f0c15b Copy

Formats

How to decode a UUID

Variant digit

Valid `01a1abe1-fa58-7071-af7e-48da03f0c15b`