Use Regex Sample Generator
Generates repeatable examples from a JavaScript-style regex using a seed. Start with the sample, select the options and run the tool. Copy or download the result after reviewing it.
Behavior and limits
Generates repeatable examples from a JavaScript-style regex using a seed. Supports character classes, alternation and bounded repetition. Lookarounds, backreferences, Unicode property escapes and special groups are rejected. Unbounded repetition is capped at 20; every generated sample is checked against the whole pattern. For test fixtures only, not passwords.
Example input
[A-Z]{2}-[0-9]{4}Expected behavior for the example
Produces ten lines such as AB-1234, each with two uppercase ASCII letters, a hyphen and four digits. The same seed repeats the exact sequence.
Check important output in the application that will consume it. Use the tool directory to find related formats and tasks.
Frequently asked questions
How does Regex Sample Generator handle my input?
Generates repeatable examples from a JavaScript-style regex using a seed. Supports character classes, alternation and bounded repetition. Lookarounds, backreferences, Unicode property escapes and special groups are rejected. Unbounded repetition is capped at 20; every generated sample is checked against the whole pattern. For test fixtures only, not passwords.
Is my input uploaded or saved automatically?
Processing runs locally in this browser. Input and results are not saved automatically. Downloads happen only when you choose them. The static preview blocks scripts and external resources when one is available.