UUID Bulk Validator
Paste a list of UUIDs to find the broken ones and the duplicates, then copy a clean list. One per line, or separated by commas or spaces.
Problems
No problems found.
| Line | Value | Problem |
|---|
The clean list has every valid ID once, in standard lowercase form, in the order you pasted them.
What the validator checks
- Length: exactly 32 hex digits.
- Characters: only 0-9 and a-f, in either case.
- Hyphens: in the 8-4-4-4-12 places, or none at all if you allow that.
- Duplicates: the same ID twice, even if written differently, such as upper and lower case.
- Version and variant: with strict mode on, the version digit must be 1 to 8 and the variant digit 8, 9, a or b.
Want to know more about one ID, such as when it was made? Paste it into the UUID decoder.
Validate a UUID in code
import { validate, version } from 'uuid';
validate('01a16818-85c0-7b3e-9f2a-4c6d81e05a73'); // true
version('01a16818-85c0-7b3e-9f2a-4c6d81e05a73'); // 7Uses the uuid package from npm. validate() only accepts the standard hyphenated form.
^[0-9a-f]{8}-[0-9a-f]{4}-[1-8][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$Strict RFC 9562 check: versions 1 to 8 and the standard variant. Match without case sensitivity. It rejects the Nil and Max UUIDs.
import uuid
def is_uuid(s: str) -> bool:
try:
uuid.UUID(s)
return True
except ValueError:
return Falseuuid.UUID() also accepts braces, urn:uuid: and missing hyphens.
SELECT '01a16818-85c0-7b3e-9f2a-4c6d81e05a73'::uuid;Casting to uuid raises an error for invalid input. PostgreSQL also accepts braces and missing hyphens.
More detail, including the edge cases a regex misses, in How to check if a string is a valid UUID.
Questions people ask
What counts as a valid UUID?
In the standard form, 32 hex digits in groups of 8-4-4-4-12, joined by hyphens. RFC 9562 also fixes a version digit (1 to 8) and a variant digit (8, 9, a or b). Turn on "Only allow standard versions" to check those too.
Is uppercase valid?
Yes. The standard says to write UUIDs in lowercase but to accept either case when reading. The clean list always comes out lowercase.
Are the Nil and Max UUIDs valid?
Yes. They are defined in RFC 9562 as special values, so the validator accepts them even in strict mode. They are rarely meant as real IDs, so the summary counts them separately.
How many IDs can I check at once?
Up to 100,000 at once.


