How to use Regular Expressions Builder
- Drop your text into the field at the top of Regular Expressions Builder.
- Set Literal text, Built pattern, Flags so the output fits your use case.
- Press Add literal and Regular Expressions Builder shows the result straight away.
- Finish by choosing Copy pattern to take the output with you.
About this tool
Regular Expressions Builder runs entirely in your browser. Regular Expressions Builder tests your regular expression against sample text in your browser, highlighting matches as you type.
Your pattern and test text stay on your device. Your input never leaves the page, and no account or install is required.
Frequently asked questions
What is Regular Expressions Builder for?
Regular Expressions Builder runs entirely on your device: add your input using the Literal text, Built pattern controls, and it processes it locally in real time.
Does Regular Expressions Builder cost anything?
No — Regular Expressions Builder is completely free, with no sign-up and no hidden limits.
Is my input private in Regular Expressions Builder?
Yes — your input never leaves your device; Regular Expressions Builder does all the work in your browser.
Which regex flavor does Regular Expressions Builder use?
Regular Expressions Builder runs your pattern with the browser's own JavaScript regex engine, live and on your device.
Does Regular Expressions Builder work on mobile?
Yes — Regular Expressions Builder is just a web page and runs on any modern browser, including phones and tablets.