Regex Tester
Test regular expressions against text. See matches and highlighted results live.
Pattern & test string
Output
Matches (0)
Enter a pattern and test string to see matches.
Highlighted test string
What is a regex tester?
A regex tester lets you try regular expressions against sample text. You enter a pattern (e.g. \w+ or [a-z]+), type or paste text, and see matches and highlighted results instantly. It helps debug patterns before using them in code or search. This tool runs in your browser and does not send data to a server.
Why test regex online?
Testing regex in an editor or terminal can be slow. An online tester gives immediate feedback as you type, so you can fix syntax errors and see which parts of the text match. Developers use it for validation rules, log parsing, and search-and-replace. All processing is client-side.
How to use this tool
Enter a regular expression in the Pattern field and the text to test in the Test string field. Results update live. Use Flags (e.g. g for global, i for case-insensitive) if needed. Invalid patterns show an error message. For related tools try JSON Formatter, Text Diff, or Hash Generator.