⚡ Validation Tool
Regex Tester
Test regular expressions against sample text and inspect matches, flags, capture groups, and match positions.
Interactive Tool
Use Regex Tester
How to use Regex Tester
- Enter the regular expression, flags, and sample text you want to test.
- Run the tester and review highlighted matches and captured groups.
- Adjust the pattern until it handles expected matches and important non-matches.
Why use Regex Tester
Regex work is easier when you can see exactly what the pattern captures. A tester helps reveal greedy matches, missing anchors, escaping mistakes, unexpected groups, and flag differences before the expression reaches application code.
This tool is useful for validation patterns, scraping helpers, route matching, log parsing, and text cleanup. A good regex should be tested against examples that should match and examples that should fail, not only the happy path.
Best for Regex Tester
- Debugging capture groups and flags.
- Testing validation patterns before coding them.
- Checking text extraction rules on real samples.
Practical notes
- Escape backslashes correctly when moving a regex into code.
- Add negative examples so the pattern is not too broad.
- Avoid using regex for formats that need a real parser.