UUID Tool
UUID Validator
Quickly tell whether a string is a real UUID, which version it is, and what variant bits it carries — useful when ingesting or debugging identifiers.
Validates v1–v8Detects version + variantFlags Nil / Max UUID
Generated locally with the Web Crypto API — nothing leaves your browser.
What Is UUID Validator?
- The validator checks the 8-4-4-4-12 shape, reads the version digit (position 14) and the variant bits (position 19), and reports what it found.
- It also recognises special values such as the Nil UUID (all zeros) and the Max UUID (all ones).
How to generate
- Paste one or many UUIDs (one per line) into the box.
- Press Validate to see version, variant and validity for each.
- Use the result to gate imports or surface bad data early.
Use Cases
- Input validation before storing or indexing identifiers.
- Debugging mismatched formats from other systems.
- Data cleaning across large imports.
How UUID Validator Compares
| Validator | Confirms format, version, variant |
| Generator | Creates new values |
| Formatter | Re-shapes existing values |
Code Examples
JavaScript
const re = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
const ok = re.test(value);Python
import uuid
try:
uuid.UUID(value)
except ValueError:
print('not a uuid')Frequently Asked Questions
What makes a UUID invalid?
A wrong length, missing hyphens, non-hex characters, or illegal version/variant bits.
Does it call a server?
No. Validation runs entirely in your browser; nothing is sent anywhere.
Is a GUID valid too?
Yes — a Microsoft GUID uses the same 128-bit layout, so it validates as an RFC 4122 / 9562 UUID with the Microsoft variant.