Write a regular expression and a test string, and see every match update live, with toggles for the common flags. Everything runs in your browser's own regex engine, so what matches here matches in your code.
How it works
- Type your RegEx pattern into the top input bar.
- Toggle expression flags such as global (g), case-insensitive (i), or multiline (m).
- Type your test string into the text area to see live, highlighted matches.
Frequently asked questions
Why should I use my browser's regex engine?
Because it is the exact same ECMAScript engine your Javascript runtime uses in production. This guarantees zero dialect surprises.
What do the specific regex flags do?
The `g` flag finds all matches instead of stopping at the first. `i` ignores upper/lower casing. `m` forces ^ and $ to match line starts/ends.
What is the difference between .* and .+ ?
.* matches zero or more characters (meaning an empty string passes), while .+ strictly requires at least one character.