What Is the Regex Builder & Tester?
The Regex Builder & Tester is a free browser tool for live pattern testing. No signup — results appear instantly.
How to Use It
Type a JavaScript-style regex, optional flags (g, i, m), and sample text. See matches, indexes, and pass/fail instantly. Need a pattern from plain English? Use the Regex Generator AI tool.
Key Features
- 100% free, unlimited client-side use
- Copy output with one click
- Works on mobile and desktop
- No account required
Frequently Asked Questions
Is the Regex Builder & Tester free?
Yes. This builder runs in your browser at no cost.
Is my data uploaded?
Client-side builders process data locally in your browser unless noted otherwise.
Can I share or print results?
Yes — copy the output into email, docs, or print from your editor.