Online Regex Tester with Live Match Highlighting
A regular expression (“regex”) is a small pattern language for finding and extracting text — the thing that powers search-and-replace, form validation, and log parsing. The tricky part is that a pattern rarely does exactly what you expect on the first try. This tester shows you live which parts of your sample text match, so you can shape the pattern with immediate feedback instead of guessing.
Frequently Asked Questions
- Is this regex tester free?
- Yes — free with no account required and no usage limits.
- Which regex flavour does it use?
- It uses JavaScript's built-in RegExp engine, which is compatible with most modern regex patterns.
- How do I test multiple flags at once?
- Check any combination of the g (global), i (case-insensitive), and m (multiline) checkboxes above the pattern field.