How to use the Regex Tester
- Enter your regular expression and flags
- Paste a test string
- See matches, groups and replacements
About this tool
Test JavaScript regular expressions with live match highlighting, capture groups and a replace preview. Regex Tester is part of ToolNest's collection of free developer tools. It works instantly in your browser with no account and no installation.
Frequently asked questions
Is the Regex Tester free to use?
Yes. Regex Tester on ToolNest is completely free, with no sign-up, no watermark and no daily limits.
Is my data private?
Yes. Regex Tester runs entirely in your browser. Your text and data are not uploaded or stored on our servers.
Does Regex Tester work on mobile phones?
Yes. ToolNest works in any modern browser on Android, iPhone, iPad, Windows, Mac and Linux. There is nothing to install.