Regular Expression Tester

About

Regular Expression Tester is Regex Validator & Highlighter.  All rolled into one!

Test and debug regular expressions directly in Chrome. Regular Expression Tester is a fast regex tester and regex validator for developers, QA, analysts, and students—built to help you verify patterns, understand matches, and fix errors with immediate feedback.

Perfect for:
✅ Developers (JavaScript regex, scraping, form validation, log parsing)
✅ QA / Localization (input validation, test cases, content checks)
✅ Data & SEO / Marketing (content analysis, pattern audits)
✅ Security-minded users (spotting sensitive data patterns)
✅ Learning (interactive practice and experimentation)

Key features:
- Regex validation with clear error messages
- Test patterns in `/pattern/flags` format (e.g., `/\\d+/g`)
- Highlight matches and navigate results
- Find and highlight matches on the current page
- Common built-in patterns (email, URL, phone, etc.) + save your own
- Works without external websites; your text stays in your browser

Why you’ll like it:
Instead of guessing whether your pattern works, you can test it instantly, see exactly what matches, and iterate safely before using it in code or workflows. It’s lightweight, distraction-free, and always one click away.

Common uses:
➤ Validate emails, phones, IDs, and form inputs
➤ Debug tricky quantifiers, groups, and lookaheads
➤ Check content rules and structured text
➤ Learn regex basics with live feedback


❓ FAQ

🤔 What is a regex?
👉 Regex (regular expression) is a pattern used to search, match, and validate text.

🖥️ I use it for JavaScript regex?
👉 The extension uses JavaScript’s regular expression engine, so it’s ideal for testing JavaScript regex behavior and flag.

📱 Does it work offline?
👉 Yes. Core regex testing and validation run locally in your browser. Some optional features may depend on the current page context, but you don’t need an external website to test patterns.

⚡ How does the regex validator work?
👉 The regex validator instantly checks if your regex pattern is valid. If there’s an error, it shows the issue, helping you verify regular expression syntax before using it in your project.

📚 Is this extension useful for beginners learning what is regex?
👉 Absolutely. If you’re asking what is a regex, this tool provides interactive learning. You can experiment with regular expression online tester features and see live results, making it easier to understand regex matching. 

🔍 Can I use the extension for data validation tasks?
👉 Yes. Many users rely on it for checking form inputs, emails, phone numbers, or structured text. With the built-in online regex tester and matcher, you can confirm if data fits the rules you’ve created.

🚀 What makes this tool different from other regex testers?
👉 Unlike typical websites, this extension is always just one click away. It combines the speed of an online regular expression tester with the convenience of being built into Chrome. Plus, it’s lightweight, fast, and distraction-free.

Install Regular Expression Tester and make regex testing faster, clearer, and easier—right inside Chrome.