What is a Regex Tester?
A regex tester is an online tool that validates regular expressions with live pattern matching and highlighting. Whether you're a developer debugging regex, a QA engineer testing validation logic, or a data analyst extracting information, our tester shows matches and captured groups instantly.
This tool provides real-time pattern matching, match highlighting, captured group display, and support for multiple flags (global, case-insensitive, multiline). Test patterns against sample text with immediate visual feedback.
Why Use a Regex Tester?
Writing correct regular expressions requires iterative testing and debugging. Developers need to verify patterns match expected inputs, identify captured groups, and test edge cases. Manual testing in code requires recompiling and running applications repeatedly.
Developers use this tester to debug regex patterns, validate matching logic, and test edge cases before implementing in code. Data engineers benefit from visual feedback that helps refine extraction patterns for text processing.
The tool provides instant visual feedback with match highlighting, shows captured groups and their values, and supports all regex flags. It's particularly valuable when debugging complex patterns, testing validation logic, and extracting structured data.
Common Use Cases
Pattern Debugging: Test and refine regex patterns with visual match highlighting.
Validation Testing: Verify input validation patterns work correctly with test cases.
Data Extraction: Test patterns for extracting specific data from text.
Capture Groups: View and verify captured group values from pattern matches.
Edge Case Testing: Test regex patterns against various input scenarios.
How to Use the Regex Tester
Using our regex tester is straightforward: enter your regular expression pattern, input test text to match against, select flags (global, multiline, case-insensitive), and view matches with highlighting and captured groups. The tool updates results in real-time as you type.
All testing is performed client-side in your browser, ensuring your patterns and test data remain private. The tester provides immediate visual feedback for rapid pattern development.