Regex Tester
Test JavaScript regular expressions live and inspect every match and group.
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Your privacy is safe, this tool runs entirely in your browser. Nothing you enter is uploaded to or stored on our servers.
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How to use Regex Tester
- 1Enter a JavaScript regular expression without slashes.
- 2Choose flags such as global, case-insensitive or multiline.
- 3Paste test text in the editor.
- 4Review live matches, indexes and capture groups.
Test JavaScript Regex Safely
The tester recompiles your expression as you type, catches syntax errors and lists every match with its source index and capture groups. It limits runaway global matching and handles zero-length matches safely.
Frequently asked questions
Which regex flavor does this tester use?
It uses the JavaScript regular expression engine built into your browser.
Should I include slash delimiters?
No. Enter only the pattern. Choose flags separately.
Does it show capture groups?
Yes. Each match lists its full value, index and numbered capture groups.
Is my test text sent anywhere?
No. Pattern matching happens locally in your browser.