What is the regex pattern for uuid (v4)?

The regex pattern for uuid (v4) is: ^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$.

How does the uuid (v4) regex work?

[0-9a-fA-F]{8}: First 8 hex characters. -: Dash separator. [0-9a-fA-F]{4}: Second group of 4 hex characters. 4[0-9a-fA-F]{3}: Version 4 indicator followed by 3 hex chars. [89abAB][0-9a-fA-F]{3}: Variant indicator (8/9/a/b) followed by 3 hex chars. [0-9a-fA-F]{12}: Final 12 hex characters.

Regex for UUID (v4)

Matches UUID version 4 format. The third group starts with 4, and the fourth group starts with 8, 9, a, or b.

Pattern

/^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}$/

Pattern Breakdown

Token	Explanation
[0-9a-fA-F]{8}	First 8 hex characters
-	Dash separator
[0-9a-fA-F]{4}	Second group of 4 hex characters
4[0-9a-fA-F]{3}	Version 4 indicator followed by 3 hex chars
[89abAB][0-9a-fA-F]{3}	Variant indicator (8/9/a/b) followed by 3 hex chars
[0-9a-fA-F]{12}	Final 12 hex characters

Test Examples

Input	Match?
550e8400-e29b-41d4-a716-446655440000	Match
6ba7b810-9dad-41d3-80b4-00c04fd430c8	No match
not-a-uuid	No match

Common Use Cases

UUID validation
Database ID format checking
API request validation

Variations

^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$

Any UUID version

Other Regex Patterns

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