Regex Tester
NewTest regular expressions interactively with real-time match highlighting, flags toggle, and a match list. Supports all JavaScript regex flags (g, i, m, s, u) and shows each match with its index position. Perfect for debugging patterns, learning regex, and validating input patterns.
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Test String0 matches
How to Use Regex Tester
- 1Enter your regex pattern
- 2Toggle flags as needed (g, i, m, s, u)
- 3Type or paste the test string
- 4See matches highlighted in real time
Your Privacy is Protected
Regex Tester runs entirely in your browser. Your files and data are never uploaded to any server, never stored, and never shared. Everything happens locally on your device using secure browser APIs.
No server uploadNo account required100% freeWorks on all devices
Frequently Asked Questions
What flags are supported?
g (global), i (case-insensitive), m (multiline), s (dotAll), u (unicode).
Why isn't my regex matching?
Check for missing flags. Without the g flag only the first match is found. Without i flag matching is case-sensitive.
Why Use This Tool?
Files never leave your device
No upload to any server
Instant processing in browser
100% free, no account needed
Tags
regex testerregular expressionregex toolregex debuggerpattern matcher