Regex Tester
Test and debug regular expressions with real-time highlighting and match counting.
Runs locally in your browser
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Regex Quick Reference
. any char · \d digit · \w word char · * 0+ · + 1+ · ? optional · ^ start · $ end · [abc] char class · () group · | or
Testing tips
Start with a small test string, confirm the first match, then add flags and groups. Use the g flag to find all matches. Remove it when you only want to inspect the first match and capture groups.
Why are zero-length matches skipped?
Patterns that match an empty string can loop forever with global matching. This tool advances past empty matches to keep the page responsive.
Which regex flavor is used?
The tester uses JavaScript regular expressions, so syntax follows the browser JavaScript engine.