Free · Keep short, middle, and long matches

Regex Coverage Pack Maker

Make a small test pack that covers several lengths and removes duplicate strings.

Real randexp.js generation
Private in your browser
Safe count and repeat caps

Make coverage pack

Enter a pattern without / slash marks. Samples are generated locally with safe count and repeat caps.

Set the pattern30 / 400 characters

Regular expressionWrite the pattern only. Example: ^[A-Z]{3}-\d{4}$

FlagsOptional. Use each flag once.Number of samples1 to 250Open repeat capCaps * and + from 1 to 40.Seed (optional)The same seed repeats the set.

Private local generatorrandexp.js 0.5.3 · no upload

Use the samplesReady when you are

Your samples will appear here

Nothing is uploaded. A safety cap keeps open-ended repeats and large batches under control.

Three simple steps

How to use it

Paste the pattern used by your form.
Generate a broad local batch.
Download the varied coverage pack.

Your pattern stays on this device

randexp.js makes every string inside this browser tab. Bookify does not upload or save the pattern, seed, or samples. Generation is capped, and random examples do not replace full validation tests.