100% Free  ·  No Signup  ·  No Upload

Regex Tester Free

Test regular expressions live. Works entirely in your browser. Your files never leave your device.

Open Regex Tester Free
No file uploadNo account needed100% privateWorks offlineAlways free
Enter a pattern and test string above.

What is Regex Tester?

Regex Tester is a free browser-based tool that runs entirely in your browser. No file uploads, no account needed, and no data stored. Fast, private and always free.

This tool lets you test regular expressions live without installing any software or creating an account. Everything runs directly in your browser for maximum privacy. Your files and data never leave your device.

Use it for quick tasks at any time from any device — desktop, tablet or mobile. No subscription, no ads, no limits.

⚡
Instant results
No server processing or wait
🔒
100% private
Files stay on your device
💰
Always free
No subscription or fees
📱
Mobile ready
Works on any device

How to use Regex Tester

  1. Open the Regex Tester tool
  2. Enter your input data or upload your file
  3. Configure the settings for your use case
  4. Download or copy the result

Why use OnlineToolsPlus?

OnlineToolsPlus processes everything locally in your browser. Your files, text and data never leave your device, which eliminates server-side privacy risks. With 200+ free tools covering PDF, image, AI writing, developer utilities, calculators, SEO, color tools and more, there is no need to juggle multiple subscriptions or install software.

Frequently asked questions

What is a regular expression?
A regular expression is a pattern that describes a set of strings. It is used to search, match, and extract text based on patterns rather than exact strings.
What regex syntax does the tester support?
JavaScript regex syntax, which covers the vast majority of common regex patterns. Lookaheads, lookbehinds, named groups, and other modern features are supported.
Can I test multiple test strings at once?
Paste multiple test strings and the tool shows which ones match the pattern and which do not.
What are the common regex flags?
g for global (find all matches), i for case-insensitive, m for multiline (^ and $ match line boundaries), and s for dotAll (. matches newlines).
Does it work offline?
Yes.
Where can I learn regex syntax?
Regular-expressions.info and MDN Web Docs are good references for regex syntax and examples.

More Developer Tools

JSON FormatterFormat, minify and validate JSONHash GeneratorSHA-256, SHA-1, SHA-512 hashingUUID GeneratorGenerate unique UUIDs v4Base64 TextEncode or decode Base64 stringsCSS MinifierMinify CSS for production

Last updated: April 11, 2026

View all 200+ free tools →