UUID Validator
Paste one UUID or a whole list to check whether each is valid — with the exact reason when it isn't, plus its version, variant, embedded time and normalized form.
Runs in your browser — nothing is uploaded Free, no limits
UUIDs to validate
How to use the UUID Validator
- Paste UUIDs, one per line — braces, urn:uuid: prefixes and hyphen-less hex are fine.
- Results appear instantly with a valid/invalid verdict and the reason for each.
- Check the version, variant and, for v1/v6/v7, the time the UUID was created.
- Copy the valid UUIDs in normalized lowercase form, or download a CSV report.
Frequently asked questions
What does a valid UUID look like?
32 hexadecimal digits (0–9, a–f), usually written in five hyphen-separated groups of 8-4-4-4-12, e.g. 550e8400-e29b-41d4-a716-446655440000. Upper and lower case are both valid; lowercase is the canonical form.
How do I tell a UUID's version?
Look at the 13th hex digit — the first digit of the third group. In 550e8400-e29b-41d4-… it's 4, so it's a random v4 UUID. A 7 there means a time-ordered v7, and 1 or 6 mean time-based UUIDs.
What is the UUID variant?
The variant is stored in the 17th hex digit (the first of the fourth group). Standard RFC 9562 UUIDs have 8, 9, a or b there; 0–7 are old NCS IDs and c–d are legacy Microsoft GUIDs.
Is a GUID the same as a UUID?
Yes. GUID is Microsoft's name for the same 128-bit identifier. GUIDs are often shown in uppercase and wrapped in braces, like {550E8400-E29B-41D4-A716-446655440000}, which this validator accepts.
Can you get the creation time from a UUID?
Only for time-based versions. v1 and v6 store a 100-nanosecond timestamp since 1582, and v7 stores Unix milliseconds in its first 48 bits. v4 UUIDs are random and contain no time.
Is the nil UUID valid?
Yes. 00000000-0000-0000-0000-000000000000 (nil) and ffffffff-ffff-ffff-ffff-ffffffffffff (max) are special values defined by RFC 9562, often used as “no value” placeholders.