Translating...
๐Ÿ‡บ๐Ÿ‡ธ English โ–ผ
๐Ÿ‡บ๐Ÿ‡ธ English ๐Ÿ‡ช๐Ÿ‡ธ Espaรฑol ๐Ÿ‡ซ๐Ÿ‡ท Franรงais ๐Ÿ‡ฉ๐Ÿ‡ช Deutsch ๐Ÿ‡ฎ๐Ÿ‡น Italiano ๐Ÿ‡ง๐Ÿ‡ท Portuguรชs ๐Ÿ‡ท๐Ÿ‡บ ะ ัƒััะบะธะน ๐Ÿ‡จ๐Ÿ‡ณ ไธญๆ–‡ ๐Ÿ‡ฏ๐Ÿ‡ต ๆ—ฅๆœฌ่ชž ๐Ÿ‡ธ๐Ÿ‡ฆ ุงู„ุนุฑุจูŠุฉ ๐Ÿ‡ฎ๐Ÿ‡ณ เคนเคฟเคจเฅเคฆเฅ€ ๐Ÿ‡ฐ๐Ÿ‡ท ํ•œ๊ตญ์–ด ๐Ÿ‡ณ๐Ÿ‡ฑ Nederlands ๐Ÿ‡ธ๐Ÿ‡ช Svenska ๐Ÿ‡ฉ๐Ÿ‡ฐ Dansk ๐Ÿ‡ณ๐Ÿ‡ด Norsk ๐Ÿ‡ซ๐Ÿ‡ฎ Suomi

๐Ÿ” Regex Tester

Professional regular expression tester and validator. Test regex patterns, validate matches, perform replacements, and debug complex expressions instantly. Real-time testing with comprehensive examples for developers.

Rate this tool
โ˜… โ˜… โ˜… โ˜… โ˜…
5.0 / 5
1 vote

๐ŸŽฏ Regular Expression Pattern

Status
Ready
Matches
0
Groups
0
Test Length
0
โŒ Regex Error
โœ… Pattern Matches

๐Ÿ“ Test String

โœจ Match Results

๐Ÿ”„ Replace Text

Why Use Our Regex Tester?

Streamline your regular expression development with professional-grade testing, validation, and debugging tools designed for developers and data analysts.

โšก Real-Time Testing

Test regular expressions instantly as you type. See matches, groups, and replacements in real-time with immediate feedback and error detection for faster development.

๐ŸŽจ Visual Match Highlighting

See your regex matches highlighted directly in the test string. Visual feedback makes it easy to understand pattern behavior and debug complex expressions.

๐Ÿ”ง Advanced Features

Support for all regex flags (global, case-insensitive, multiline, dot-all), capture groups, lookaheads, lookbehinds, and complex pattern matching.

๐Ÿ”’ Privacy Focused

All regex testing happens locally in your browser. Your patterns and test data never leave your device, ensuring complete privacy and security.

๐Ÿš€ Developer Friendly

Built for developers by developers. Features include copy/paste shortcuts, downloadable results, common regex examples, and comprehensive error messages.

๐Ÿ“ฑ Cross-Platform

Works seamlessly across all devices and browsers. Test regex patterns from anywhere, anytime, with full JavaScript RegExp compatibility.

Common Regex Examples

Click on any example to load it into the tester and see how it works.

๐Ÿ“ง Email Validation

Validate email addresses with comprehensive pattern matching for local and domain parts including international formats.

[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

๐Ÿ“ฑ Phone Numbers

Match various phone number formats including US, international, with/without country codes and different separators.

(\+\d{1,3}\s?)?\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}

๐ŸŒ URLs & Links

Extract and validate URLs including HTTP/HTTPS protocols, subdomains, paths, query parameters, and fragments.

https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}...

๐Ÿ” Password Strength

Validate password complexity requiring uppercase, lowercase, numbers, special characters, and minimum length.

^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$

Frequently Asked Questions

Common questions about regular expressions, testing, and best practices.

What are regular expressions and why are they useful? +
Regular expressions (regex) are powerful pattern-matching tools used to search, validate, and manipulate text. They're essential for data validation, text processing, search and replace operations, and parsing structured data. Regex saves time and provides precise control over text matching operations.
Is my data safe when using this regex tester? +
Yes, absolutely. Our regex tester processes all data locally in your browser. No regex patterns, test strings, or sensitive data is sent to external servers or stored anywhere. Your patterns and data remain completely private and secure on your device.
What regex flags does this tool support? +
Our tester supports all major JavaScript regex flags: Global (g) for finding all matches, Ignore Case (i) for case-insensitive matching, Multiline (m) for line-by-line matching, and Dot All (s) for dot matching newlines. These flags can be combined for complex pattern matching.
How do I use capture groups in regex? +
Capture groups are created using parentheses () in your regex pattern. They allow you to extract specific parts of matches. For example, in the pattern (\d{3})-(\d{3})-(\d{4}) for phone numbers, each group captures a different part. Use $1, $2, $3 in replacements to reference captured groups.
What's the difference between greedy and lazy matching? +
Greedy matching (default) tries to match as many characters as possible. Lazy matching (using ? after quantifiers like *?, +?, {n,m}?) matches as few characters as possible. For example, .* matches everything, while .*? stops at the first occurrence. This is crucial for HTML parsing and nested structures.
How can I test regex for different programming languages? +
Our tester uses JavaScript regex engine, which is compatible with most modern programming languages for basic patterns. However, some languages have specific features or syntax differences. The patterns you test here will work in JavaScript, Python (with minor adjustments), Java, C#, and most other languages for common use cases.
What are lookaheads and lookbehinds in regex? +
Lookaheads (?=...) and lookbehinds (?<=...) are zero-width assertions that match positions, not characters. Positive lookahead (?=pattern) matches if pattern follows, negative (?!pattern) matches if pattern doesn't follow. Lookbehinds work similarly but check what comes before. They're perfect for complex validation rules.
How do I escape special characters in regex? +
Special regex characters (.^$*+?{}[]|\()) need to be escaped with backslashes to match literally. For example, to match a literal dot, use \. instead of just . To match a dollar sign, use \$. The backslash tells the regex engine to treat the character literally rather than as a special operator.
Can I test regex performance with this tool? +
While our tool doesn't provide detailed performance metrics, you can test regex efficiency by observing response time with large test strings. Avoid catastrophic backtracking by being careful with nested quantifiers and alternations. For production applications, always test regex performance with representative data sizes.
How do I create regex for complex data validation? +
Start simple and build complexity gradually. Use anchors (^ and $) for full string matching, combine character classes [a-zA-Z0-9], quantifiers {min,max}, and groups (). Test each component separately, then combine. For complex validation like credit cards or addresses, consider breaking into multiple simpler patterns.
What's the best way to learn regex patterns? +
Start with our example patterns and modify them to understand how changes affect matches. Practice with real data from your projects. Learn one concept at a time: character classes, quantifiers, groups, then advanced features. Use tools like this tester to experiment safely and see immediate results.
Is this regex tester free to use? +
Yes, our regex tester is completely free to use with no registration required. You can test unlimited patterns, validate expressions, perform replacements, and download results without any charges. The tool is designed to be accessible to developers and students worldwide.