Pattern String Generator
Generated locally in your browser with the Web Crypto API. Placeholders are replaced with secure random characters; every other character passes through unchanged.
Custom-format codes
Build a random value that follows your own format mask — license keys, invoice codes, fixtures, and mock external IDs whose shape you control. Type a pattern and each placeholder is filled with a secure random character.
- #
- a random digit 0-9
- ?
- a random uppercase letter A-Z
- *
- a random uppercase alphanumeric A-Z0-9
- \
- escape — emit the next character literally