Regex Tester - Online Regular Expression Tool
Test and debug your regular expressions instantly. Enter your regex pattern and test string to see matches, groups, and replacements in real-time.
Regex Test
Results
About the Regex Tester
This online Regex Tester helps you quickly validate and understand regular expressions. It highlights matches and captures groups, and allows you to test replacement patterns.
How to Use
Enter your regular expression in the 'Regular Expression' field. Provide the text you want to test against in the 'Test String' area. Select flags like Global, Multiline, or Ignore Case as needed. Click 'Test Regex' to see the matches highlighted. You can also enter a 'Replacement String' and click 'Perform Replacement' to see the result of a substitution.
Frequently Asked Questions
What are regular expressions?
Regular expressions (regex or regexp) are sequences of characters that define a search pattern. They are used for pattern matching with strings, or for finding and replacing operations.
What do the flags (g, m, i) mean?
- Global (g): Finds all matches rather than stopping after the first match.
- Multiline (m): Treats the beginning (^) and end ($) anchors as matching the start/end of each line, not just the start/end of the entire string.
- Ignore Case (i): Performs case-insensitive matching.
How do I learn more about regex?
There are many online resources and tutorials available. Websites like regex101.com or regular-expressions.info provide comprehensive guides and interactive testers.