Regex Tester
Test regular expressions instantly with our free regex tester and regex tester online tool. Use the regex checker, regular expression tester, and regex test features to determine whether your patterns match the expected text. Our tool can also function as a regex validator, regex tester online free, and regular expression tester online for developers and programmers. Use the regex debugger, regex checker online, and test regex functionality to troubleshoot patterns and find matching results. Wondering how do I test a regular expression, how do I check if a regex works, or how can I test regex online? Enter your pattern and test it instantly.
How to use the Regex Tester
- Enter the pattern and flags.
- Paste test text.
Regex Tester features and limits
- Shows index and capture groups, up to 200 matches
- Limitation: JavaScript syntax only, and patterns with heavy backtracking can freeze the tab.
How the Regex Tester works
The pattern is compiled with RegExp and matchAll collects results.
Privacy and browser processing
Your input is processed locally in this page and is not uploaded or stored by Best Web Tools. Your hosting provider may still keep ordinary server logs for page requests.
Frequently asked questions
Why do I get no matches?
Check flags such as i, anchors and escaping.
Related tools
Browse all Developer Tools or return to the Best Web Tools homepage.
Why use the Regex Tester?
Regex behaves differently between languages. Testing in the same engine your code will use avoids surprises.