Common Presets
//
Flags:/.../g
0 matches
Matches will appear here...
$
Regex Tester
Test regular expressions with real-time match highlighting, captured groups, and replace functionality.
What Are Regular Expressions?
Regular expressions (regex) are patterns that describe sets of strings. They power search, validation, and text transformation in virtually every programming language, from parsing log files to validating email addresses.
How This Tester Works
Type a regex pattern and paste your test string. Matches highlight in real time, captured groups are listed with their indices, and you can toggle flags like global, case-insensitive, multiline, and dotAll.
Built-In Presets and Replace
Choose from common presets like email, URL, or IP address patterns to jumpstart your work. The find-and-replace mode lets you test substitution patterns before using them in your code.