UUID Validator & Decoder: Version, Variant, Timestamp

Valid 01a1d280-f275-71e7-b70d-d07cf0333b75

Version 7 Unix Epoch time-based Sortable by time

01a1d280f275 unix_ts_ms

7 ver

1e7 rand_a

b70dd07cf0333b75 var + rand_b

Version	7 Unix Epoch time-based
Variant	RFC 9562 (formerly RFC 4122 / DCE 1.1) (bits `10`)
Timestamp (UTC)	`2026-11-13T01:23:48.469Z` Unix: 1794533028469 ms. Milliseconds.

Version

7 Unix Epoch time-based

Variant

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

Timestamp (UTC)

2026-11-13T01:23:48.469Z
Unix: 1794533028469 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)	`01a1d280-f275-71e7-b70d-d07cf0333b75`
Uppercase	`01A1D280-F275-71E7-B70D-D07CF0333B75`
Microsoft GUID (braces)	`{01A1D280-F275-71E7-B70D-D07CF0333B75}`
URN	`urn:uuid:01a1d280-f275-71e7-b70d-d07cf0333b75`
32 hex digits	`01a1d280f27571e7b70dd07cf0333b75`
Base64 (RFC byte order)	`AaHSgPJ1cee3DdB88DM7dQ==`
128-bit integer (decimal)	`2169457312267946397182749525996157813`
.NET Guid.ToByteArray() (hex)	`80d2a10175f2e771b70dd07cf0333b75`
.NET Guid bytes (Base64)	`gNKhAXXy53G3DdB88DM7dQ==`

Standard (lowercase)

01a1d280-f275-71e7-b70d-d07cf0333b75

Uppercase

01A1D280-F275-71E7-B70D-D07CF0333B75

Microsoft GUID (braces)

{01A1D280-F275-71E7-B70D-D07CF0333B75}

URN

urn:uuid:01a1d280-f275-71e7-b70d-d07cf0333b75

32 hex digits

01a1d280f27571e7b70dd07cf0333b75

Base64 (RFC byte order)

AaHSgPJ1cee3DdB88DM7dQ==

128-bit integer (decimal)

2169457312267946397182749525996157813

.NET Guid.ToByteArray() (hex)

80d2a10175f2e771b70dd07cf0333b75

.NET Guid bytes (Base64)

gNKhAXXy53G3DdB88DM7dQ==

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 01a1d280-f275-71e7-b70d-d07cf0333b75 Copy

Formats

How to decode a UUID

Variant digit

Valid `01a1d280-f275-71e7-b70d-d07cf0333b75`