输入模式和测试字符串
Learn More About Regular Expressions
Master regex syntax and common patterns:
About Regex Tester
Writing and debugging Regular Expressions (Regex) can be a headache. Our free online Regex Tester provides a real-time environment to test your patterns against sample text, highlighting matches and explaining the syntax.
How It Works
The tool uses JavaScript's native RegExp engine to evaluate your pattern against the provided test string in real-time. It parses the results to highlight matching substrings and capture groups directly in the text editor.
Common Use Cases
- Testing a regex pattern for validating email addresses or phone numbers
- Debugging complex search-and-replace operations before running them in code
- Extracting specific data points (like dates or URLs) from a large block of text
- Learning and experimenting with different regex syntax and flags
Frequently Asked Questions
The tool uses the JavaScript (ECMAScript) regex engine, as it runs directly in your browser. Most standard regex syntax is supported, but specific features from PCRE or Python may behave differently.
No, everything is evaluated locally in your browser. Your patterns and test data are not saved or transmitted to any server.