How to use Regex Builder Online
- Paste the pattern and test string you need to process into the input box.
- Set Literal text, Built pattern, Flags so the output fits your use case.
- Hit Add literal — the processed output appears below at once.
- Use Copy pattern to keep or reuse the result.
About this tool
Regex Builder Online runs entirely in your browser. Regex Builder Online runs your pattern locally with the JavaScript engine and shows captures live.
Your pattern and test text stay on your device. It behaves the same on desktop and mobile, with nothing stored remotely.
Frequently asked questions
What is Regex Builder Online for?
Use Regex Builder Online to process your input without installing anything using the Literal text, Built pattern controls; everything happens client-side.
Do I need an account for Regex Builder Online?
No — Regex Builder Online needs no account, sign-up or installation.
Is my input private in Regex Builder Online?
Yes — your input never leaves your device; Regex Builder Online does all the work in your browser.
Which regex flavor does Regex Builder Online use?
Regex Builder Online runs your pattern with the browser's own JavaScript regex engine, live and on your device.
Does Regex Builder Online work on mobile?
Yes — Regex Builder Online is just a web page and runs on any modern browser, including phones and tablets.