CEZAMRegex tester
Highlighted matches, named groups.
| # | Index | Match | Groups |
|---|---|---|---|
| 1 | 10–33 | jean.dupont@example.com | — |
| 2 | 44–65 | support@cezam.example | — |
- 100% local — your data never leaves your browser
- Free, no usage limits
- No sign-up, no account
What this tool does
The tool runs your pattern with the browser’s native RegExp engine — exactly the syntax and behaviour of JavaScript in production. Matches are highlighted in the test text, and each one is detailed with its position (start and end index) and its capture groups, both numbered and named.
Everything happens in your browser: neither the pattern nor the text is sent anywhere. The g, i, m, s and u flags toggle with one click and the result updates as you type.
Limitations
The syntax is JavaScript’s, not PCRE’s: no possessive quantifiers or recursive patterns, and a few character classes differ. To stay responsive, the test text is truncated at 100,000 characters and display stops at the first 2,000 matches — the tool says so when it happens.
A pattern prone to catastrophic backtracking (for instance nested quantifiers over a long text) can freeze the tab while it computes: that is a limit of the engine itself, not of the tool.