Regex Tester
Test your regular expressions against sample text. See all matches instantly with support for common regex flags. Perfect for debugging and validating patterns.
How It Works
Enter your regex pattern and optional flags
Paste the text you want to test against
Click "Test" to find all matches
Features
Frequently Asked Questions
Is this tool really free?
Yes, 100% free with no hidden costs or limits. All processing happens in your browser.
Are my files secure?
Absolutely. All regex testing happens locally in your browser – your data never leaves your device.
What regex flags are supported?
We support g (global), i (case-insensitive), m (multiline), s (dotAll), and u (unicode) flags.
Regex Tester Online — The Complete Guide
Test regex online with our free regular expression tester. Validate patterns, match text, and debug regex online in real-time — essential for developers working with text processing and validation.
Regex Validator Free
Our regex validator free tool checks your pattern syntax instantly. See errors highlighted as you type, with explanations of what went wrong. No more guessing why your regex does not work.
Regex Pattern Matcher
The regex pattern matcher highlights all matches in your test string. See exactly what your regex captures, including groups. Color-coded highlighting shows matched portions clearly.
Regex Checker with Flags
Our regex checker supports all standard flags: global (g), case-insensitive (i), multiline (m), dotAll (s), and unicode (u). Toggle flags to see how they affect your pattern matching.
Tips for Working with Regex
- Start simple and build complexity gradually
- Use capturing groups () to extract specific parts
- Test with edge cases including empty strings
- All processing happens locally — your data stays private