Regex Tester
Type a regular expression and a test string to see matches highlighted instantly, along with capture groups and a running match count — all directly in your browser, nothing is sent to a server.
How it works
Enter a pattern and optionally toggle flags like g (global), i (case-insensitive), m (multiline) or s (dot matches newline). Matches are highlighted in the test string below as you type, and any capture groups are listed separately.
Tip
Use the g flag to find every match in the text instead of only the first one. Parentheses ( ) in your pattern create numbered capture groups you can see listed under each match.
What if my pattern is invalid?
If the pattern can't be compiled, an error message appears instead of the highlighted text — fix the pattern and the preview updates automatically.
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