UUID Validator & Decoder: Version, Variant, Timestamp

Valid 01a1d997-6a08-7179-b3b3-1a2f677dfaa0

Version 7 Unix Epoch time-based Sortable by time

01a1d9976a08 unix_ts_ms

7 ver

179 rand_a

b3b31a2f677dfaa0 var + rand_b

Version	7 Unix Epoch time-based
Variant	RFC 9562 (formerly RFC 4122 / DCE 1.1) (bits `10`)
Timestamp (UTC)	`2026-11-14T10:25:41.384Z` Unix: 1794651941384 ms. Milliseconds.

Version

7 Unix Epoch time-based

Variant

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

Timestamp (UTC)

2026-11-14T10:25:41.384Z
Unix: 1794651941384 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)	`01a1d997-6a08-7179-b3b3-1a2f677dfaa0`
Uppercase	`01A1D997-6A08-7179-B3B3-1A2F677DFAA0`
Microsoft GUID (braces)	`{01A1D997-6A08-7179-B3B3-1A2F677DFAA0}`
URN	`urn:uuid:01a1d997-6a08-7179-b3b3-1a2f677dfaa0`
32 hex digits	`01a1d9976a087179b3b31a2f677dfaa0`
Base64 (RFC byte order)	`AaHZl2oIcXmzsxovZ336oA==`
128-bit integer (decimal)	`2169601069161173507531003799462083232`
.NET Guid.ToByteArray() (hex)	`97d9a101086a7971b3b31a2f677dfaa0`
.NET Guid bytes (Base64)	`l9mhAQhqeXGzsxovZ336oA==`

Standard (lowercase)

01a1d997-6a08-7179-b3b3-1a2f677dfaa0

Uppercase

01A1D997-6A08-7179-B3B3-1A2F677DFAA0

Microsoft GUID (braces)

{01A1D997-6A08-7179-B3B3-1A2F677DFAA0}

URN

urn:uuid:01a1d997-6a08-7179-b3b3-1a2f677dfaa0

32 hex digits

01a1d9976a087179b3b31a2f677dfaa0

Base64 (RFC byte order)

AaHZl2oIcXmzsxovZ336oA==

128-bit integer (decimal)

2169601069161173507531003799462083232

.NET Guid.ToByteArray() (hex)

97d9a101086a7971b3b31a2f677dfaa0

.NET Guid bytes (Base64)

l9mhAQhqeXGzsxovZ336oA==

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 01a1d997-6a08-7179-b3b3-1a2f677dfaa0 Copy

Formats

How to decode a UUID

Variant digit

Valid `01a1d997-6a08-7179-b3b3-1a2f677dfaa0`