UUID Validator & Decoder: Version, Variant, Timestamp

Valid 01a1cc6e-a6e2-72e8-aeeb-0fd9272bfb13

Version 7 Unix Epoch time-based Sortable by time

01a1cc6ea6e2 unix_ts_ms

7 ver

2e8 rand_a

aeeb0fd9272bfb13 var + rand_b

Version	7 Unix Epoch time-based
Variant	RFC 9562 (formerly RFC 4122 / DCE 1.1) (bits `10`)
Timestamp (UTC)	`2026-11-11T21:06:06.178Z` Unix: 1794431166178 ms. Milliseconds.

Version

7 Unix Epoch time-based

Variant

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

Timestamp (UTC)

2026-11-11T21:06:06.178Z
Unix: 1794431166178 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)	`01a1cc6e-a6e2-72e8-aeeb-0fd9272bfb13`
Uppercase	`01A1CC6E-A6E2-72E8-AEEB-0FD9272BFB13`
Microsoft GUID (braces)	`{01A1CC6E-A6E2-72E8-AEEB-0FD9272BFB13}`
URN	`urn:uuid:01a1cc6e-a6e2-72e8-aeeb-0fd9272bfb13`
32 hex digits	`01a1cc6ea6e272e8aeeb0fd9272bfb13`
Base64 (RFC byte order)	`AaHMbqbicuiu6w/ZJyv7Ew==`
128-bit integer (decimal)	`2169334168314316138544882747815230227`
.NET Guid.ToByteArray() (hex)	`6ecca101e2a6e872aeeb0fd9272bfb13`
.NET Guid bytes (Base64)	`bsyhAeKm6HKu6w/ZJyv7Ew==`

Standard (lowercase)

01a1cc6e-a6e2-72e8-aeeb-0fd9272bfb13

Uppercase

01A1CC6E-A6E2-72E8-AEEB-0FD9272BFB13

Microsoft GUID (braces)

{01A1CC6E-A6E2-72E8-AEEB-0FD9272BFB13}

URN

urn:uuid:01a1cc6e-a6e2-72e8-aeeb-0fd9272bfb13

32 hex digits

01a1cc6ea6e272e8aeeb0fd9272bfb13

Base64 (RFC byte order)

AaHMbqbicuiu6w/ZJyv7Ew==

128-bit integer (decimal)

2169334168314316138544882747815230227

.NET Guid.ToByteArray() (hex)

6ecca101e2a6e872aeeb0fd9272bfb13

.NET Guid bytes (Base64)

bsyhAeKm6HKu6w/ZJyv7Ew==

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 01a1cc6e-a6e2-72e8-aeeb-0fd9272bfb13 Copy

Formats

How to decode a UUID

Variant digit

Valid `01a1cc6e-a6e2-72e8-aeeb-0fd9272bfb13`