Test a regular expression online 12 uses
Test a JavaScript regular expression against sample text and see every match highlighted live.
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- Runs entirely in your browser — your text is never sent to a server
- Uses JavaScript's native RegExp engine, with every match highlighted live
- Free, no account required
How it works
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1
Paste the string, expression, or value you want to inspect.
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2
It's parsed instantly and broken down on screen.
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3
Review the details or matches highlighted for you.
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4
Copy any part of the result you need.
Why use this tool
Every dev utility, one place
Format, convert, encode, decode, and generate — no more juggling ten tabs.
100% private, always
Every tool runs in your browser — your code and data are never sent anywhere.
Works on any device
Runs on Windows, Mac, Linux, iOS, and Android — nothing to install.
Instant results
No queues, no build step — results update as you type.
Built to handle real data
Full Unicode support and RFC-compliant parsing, edge cases included.
Free, always
Free to use, with no rate limits, sign-up, or trial period.
Frequently asked questions
It utilizes the native JavaScript RegExp engine, which is highly compatible with most modern web development.
Yes, modern browser engines fully support positive and negative lookbehinds in their regex implementations.
You can easily toggle global, case-insensitive, and multiline flags directly from the interface.
Each captured subgroup is highlighted in a distinct color to clearly separate it from the full match.
Extremely complex expressions can cause catastrophic backtracking; ensure your patterns are optimized.
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