UUID Validator & Decoder: Version, Variant, Timestamp

Valid 01a1d07c-fdc0-7197-b941-3397df49294a

Version 7 Unix Epoch time-based Sortable by time

01a1d07cfdc0 unix_ts_ms

7 ver

197 rand_a

b9413397df49294a var + rand_b

Version	7 Unix Epoch time-based
Variant	RFC 9562 (formerly RFC 4122 / DCE 1.1) (bits `10`)
Timestamp (UTC)	`2026-11-12T16:00:14.784Z` Unix: 1794499214784 ms. Milliseconds.

Version

7 Unix Epoch time-based

Variant

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

Timestamp (UTC)

2026-11-12T16:00:14.784Z
Unix: 1794499214784 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)	`01a1d07c-fdc0-7197-b941-3397df49294a`
Uppercase	`01A1D07C-FDC0-7197-B941-3397DF49294A`
Microsoft GUID (braces)	`{01A1D07C-FDC0-7197-B941-3397DF49294A}`
URN	`urn:uuid:01a1d07c-fdc0-7197-b941-3397df49294a`
32 hex digits	`01a1d07cfdc07197b9413397df49294a`
Base64 (RFC byte order)	`AaHQfP3AcZe5QTOX30kpSg==`
128-bit integer (decimal)	`2169416434031092105709497683848800586`
.NET Guid.ToByteArray() (hex)	`7cd0a101c0fd9771b9413397df49294a`
.NET Guid bytes (Base64)	`fNChAcD9l3G5QTOX30kpSg==`

Standard (lowercase)

01a1d07c-fdc0-7197-b941-3397df49294a

Uppercase

01A1D07C-FDC0-7197-B941-3397DF49294A

Microsoft GUID (braces)

{01A1D07C-FDC0-7197-B941-3397DF49294A}

URN

urn:uuid:01a1d07c-fdc0-7197-b941-3397df49294a

32 hex digits

01a1d07cfdc07197b9413397df49294a

Base64 (RFC byte order)

AaHQfP3AcZe5QTOX30kpSg==

128-bit integer (decimal)

2169416434031092105709497683848800586

.NET Guid.ToByteArray() (hex)

7cd0a101c0fd9771b9413397df49294a

.NET Guid bytes (Base64)

fNChAcD9l3G5QTOX30kpSg==

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 01a1d07c-fdc0-7197-b941-3397df49294a Copy

Formats

How to decode a UUID

Variant digit

Valid `01a1d07c-fdc0-7197-b941-3397df49294a`