Shows each match with its index and capture groups, with toggles for the case-insensitive, multiline and dot-all flags. Syntax errors are reported rather than thrown, and zero-length matches will not hang the page.
Runs entirely in your browser
Test a regular expression against sample text and see exactly what it matches. This tool highlights every match with its position and any capture groups, and gives you toggles for the case-insensitive, multiline and dot-all flags so you can replicate the behaviour of the pattern in your code.
It is built to be safe and helpful while you experiment: syntax errors in the pattern are reported rather than thrown, and zero-length matches — a classic way to hang a regex tool in an infinite loop — are handled so the page stays responsive. Seeing the capture groups is often the key to understanding why a pattern does or does not do what you expected.
It runs in your browser, so the text and pattern you test stay on your device. Use it to develop a pattern, debug one that is matching too much or too little, or learn how a flag changes behaviour.
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