Developer Tools
Regex Tester
FreeNo SignupPrivate — runs in your browser
Test and debug regular expressions online for free with real-time matching and group extraction. Supports JavaScript regex syntax. No signup required.
What is Regex Tester?
Regular expressions are powerful but tricky to get right. Our free Regex Tester lets you write, test, and debug regular expressions in real time. See matches highlighted instantly in your test text, extract capture groups, and toggle flags — all with JavaScript's native regex engine.
How to Use Regex Tester
- 1Enter your regex pattern
- 2Type or paste test text
- 3See matches highlighted in real time
- 4View capture groups and match details
Key Features & Benefits
Real-time matching with syntax highlighting
Full capture group extraction
All standard JavaScript regex flags
Match count and performance timing
Frequently Asked Questions
Which regex flavor does this use?
It uses JavaScript's native RegExp engine, which is compatible with most modern languages and tools.
Does it show capture groups?
Yes, all named and numbered capture groups are highlighted and listed separately.
Can I use regex flags?
Yes, you can toggle global (g), case-insensitive (i), multiline (m), dotAll (s), and Unicode (u) flags.