🔣 Regex Tester
Test regular expressions with live match highlighting. Supports flags, capture groups, and match details — all in your browser, no upload, instant results.
About the Regex Tester
This regex tester runs entirely in your browser. Enter a regular expression, pick flags, paste your test text, and click Test to see matches highlighted instantly. Nothing is uploaded to a server — all matching happens with JavaScript on your device.
Supported flags
- g — Global match. Finds all matches in the string instead of stopping at the first one.
- i — Case-insensitive match. Ignores letter case when comparing.
- m — Multiline mode. Makes
^and$match the start and end of each line, not just the whole string.
How to use the tester
- Type your regex pattern in the input box (without the surrounding slashes).
- Select the flags you need from the dropdown.
- Paste or type the text you want to test against.
- Click Test to run the match. Results show the total count, each match with its index, captured groups, and the highlighted text.
- Click Clear to reset everything.
Frequently asked questions
Do I need to wrap my pattern in slashes? No. Just type the pattern itself, for example \d+ to match numbers. The slashes are added automatically.
What happens if my pattern is invalid? The tool shows an error message describing the problem so you can fix the syntax.
Are capture groups supported? Yes. Each match lists its numbered capture groups, so you can inspect exactly what each part of your pattern matched.
Does this tool send my text anywhere? No. All processing is local. Your input never leaves your browser.