The Regex Tester lets you build and debug regular expressions with instant feedback. Type a pattern and choose the flags (global, ignore-case, multiline, dotall), paste your test text, and every match is highlighted live as you type, with a running match count. It also lists numbered and named capture groups from the first match and includes a library of ready-made patterns — email, CPF, CEP, Brazilian phone, URL, IPv4 and dates — plus a quick reference of the most common syntax tokens. Everything uses your browser’s native JavaScript regex engine and runs locally, so your patterns and text stay private.
How to Use the Regex Tester
- Type a regular expression and toggle the flags (g, i, m, s) you need.
- Paste text below — matches are highlighted instantly with a count.
- Inspect the capture groups, or click a common pattern to start from a template.
Benefits and Use Cases
- Build and debug patterns for validation, parsing and search-and-replace in seconds.
- Learn regex faster with live highlighting, group inspection and a built-in cheat sheet.
- Runs entirely in your browser, so your patterns and test data are never uploaded.