Regex Generator & Tester
Generate regex from plain English or test your patterns
✓ Runs 100% in your browser — no data sent to serversFrequently Asked Questions
What is a regular expression?
A regular expression (regex) is a sequence of characters that defines a search pattern. It's used for pattern matching in strings, validating input formats, finding and replacing text, and extracting data. Regex is supported in most programming languages.
How do I use the AI Generate feature?
Click "AI Generate" and describe what you want to match in plain English (e.g., "email addresses" or "phone numbers in format XXX-XXX-XXXX"). The AI will generate a regex pattern for you, which you can then test and refine.
What do the regex flags mean?
Global (g) finds all matches instead of stopping after the first. Case Insensitive (i) makes the pattern match regardless of letter case. Multiline (m) makes ^ and $ match the start/end of each line instead of the whole string.
Why aren't my matches showing up?
Check that your regex pattern is valid and properly escaped. Common issues include forgetting to escape special characters like dots (.), using the wrong flags, or having syntax errors in your pattern. The tool will highlight all matches when the pattern is valid.
Can I test regex for different programming languages?
This tool uses JavaScript regex syntax, which is similar to most languages but has some differences. The core patterns work across languages, but some advanced features or escape sequences may vary. Always test in your target language's environment.
How do I match special characters?
Special regex characters like . * + ? [ ] ( ) { } ^ $ | \ need to be escaped with a backslash (\) to match them literally. For example, to match a literal dot, use \. instead of just .