Regex Tester
Write, test, and debug Regular Expressions instantly in your browser.
Matched text will be highlighted here.
About the Regex Tester Engine
Writing Regular Expressions (Regex) can feel like writing a foreign language. A single missing backslash can break an entire data extraction pipeline. The OnlinePaste.com Regex Tester provides a safe, visual environment to test your patterns against real data before deploying them to your application.
Live Highlighting
Our engine evaluates your Regex natively in Javascript as you type. If your pattern successfully matches parts of your test string, it instantly highlights those sections in blue. This immediate visual feedback makes it incredibly easy to see if you are capturing too much data, or missing edge cases.
Capture Group Extraction
Advanced regular expressions use parentheses `()` to create "Capture Groups", allowing you to extract specific substrings (like parsing the domain name out of an email address). Click the Match Details tab to see a perfectly parsed list of every match, index, and sub-group isolated by your engine.