About the Regex Tester
Write and test regular expressions against your own text with live match highlighting and capture-group breakdowns. This free online regex tester is built for developers who want instant feedback without leaving the browser.
Why this tool is useful
- Validate patterns before dropping them into code.
- See exactly what your regex matches, group by group.
- Learn regex faster with immediate visual feedback.
How it works (client-side)
- Enter your regex and choose flags (global, case-insensitive, etc.).
- Paste the test text below.
- Matches and capture groups highlight instantly as you type.
Frequently asked questions
Which regex flavor is supported?
JavaScript's native RegExp flavor, which covers the vast majority of everyday patterns.
Can I use flags?
Yes — global (g), case-insensitive (i), multiline (m), and more can be toggled.
Is my text uploaded?
No. Matching runs entirely in your browser.