Regex Example

JWT Segment Pattern

Validates a URL-safe Base64 JWT segment.

Regex Pattern

^[A-Za-z0-9_-]+$

Test Cases

  • eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9 - match
  • abc+/== - no match
  • abc_123-XYZ - match

Edge Cases

  • Does not verify JWT structure or signature.
  • Padding is optional in Base64URL encoding.