About this tool
Regular expressions are powerful but notoriously easy to get subtly wrong — a pattern that seems to match your first test case can fail silently on edge cases you didn't think to check. This tool lets you write a pattern and immediately see it applied against real test text, with matches highlighted live as you type, capture groups broken out individually, and support for common flags like global, case-insensitive, and multiline matching. Instead of guessing and re-running code to debug a regex, you can iterate on the pattern directly and watch the highlighting update in real time until it matches exactly what you intend — and nothing more. Testing runs entirely in your browser using JavaScript's native regex engine.
Frequently asked questions
Which regex flavor does it use?
It uses JavaScript's native regular expression engine, so syntax and behavior match what you'd get using regex directly in JavaScript code.
Does it show capture groups separately?
Yes — each capture group in a match is broken out individually so you can verify your groups are extracting exactly what you expect.
What flags are supported?
Common flags including global (g), case-insensitive (i), and multiline (m) are supported and can be toggled while testing.
Why does my pattern only match the first occurrence?
Without the global (g) flag, most regex operations stop after the first match — enable global matching to find every occurrence in the text.
Can I test against multi-line text?
Yes, you can paste multi-line test text and use the multiline flag to control whether ^ and $ match the start/end of each line versus the whole string.