Free Privacy ToolsRegex Tester
Test regular expressions with live match highlighting and capture groups. Free, unlimited, private — works entirely in your browser.
How to use
- Type your regular expression (without surrounding / slashes).
- Pick flags: g finds all matches, i ignores case, m treats each line separately.
- Paste your test text and click Test Regex.
- Matches are highlighted and capture groups are listed below.
FAQ
Is it really free?
Yes — every tool on this site is 100% free with no limits, no signup and no watermarks.
Is my data private?
Absolutely. All processing happens locally in your browser. Your pattern and test text are never uploaded to any server.
Which regex flavor is this?
JavaScript regular expressions, the same engine used in browsers and Node.js. Most common syntax works the same in Python, PHP and other languages.
Complete Guide to Regular Expressions
Regular expressions (regex) are patterns for finding and validating text: email addresses, phone numbers, URLs, dates, or anything with a shape. A few building blocks cover most jobs: \d matches a digit, \w a word character, . any character, + means "one or more", * means "zero or more", and \b marks a word boundary. Parentheses (...) capture groups you can reuse or extract.
Two habits save hours: test against real examples, including the ones that should not match, and keep patterns as simple as the job allows. A pattern that matches too much is usually worse than one that matches too little. This tester runs entirely in your browser — your patterns and test data never leave your device.