Regular Expression Tester
Test, debug, and learn regular expressions with real-time matching and intelligent analysis
7 Core Feature Modules
Comprehensive regex testing, learning, and optimization platform
Test regular expressions in real-time with 4 testing modes (match, replace, split, test). Automatically displays match results, capture groups, named groups, and execution time to help you quickly verify regex correctness.
💡 Validate user input formats, extract text content, perform text replacement operations
Provides 8 verified common regex templates including email, phone, URL, IPv4 address, color codes, dates, passwords, and HTML tags. Supports category filtering and search, one-click apply to tester.
💡 Quickly use standard regex patterns, save writing time, ensure pattern accuracy
Breaks down complex regular expressions into understandable parts with detailed explanations for each component. Automatically identifies literals, metacharacters, quantifiers, groups, character classes, and anchors, evaluates overall complexity.
💡 Learn and understand regex written by others, master advanced regex techniques
Runs 1000 iteration tests to detect regex performance issues. Automatically identifies catastrophic backtracking risks, evaluates time complexity (low/medium/high/catastrophic), provides specific optimization suggestions.
💡 Performance testing before production deployment, avoid regex-related performance issues
Batch test multiple strings with regex, supports manual input and file upload. Each test item shows independent match status (success/no match/error) and match count for comprehensive regex validation.
💡 Test edge cases, verify regex handling of various inputs
Generate ready-to-use regex code for 8 programming languages (JavaScript, Python, Java, PHP, C#, Go, Ruby, Swift). Automatically converts regex flags, provides complete examples for testing, matching, replacing, and splitting.
💡 Quickly integrate tested regex into project code
Automatically saves the last 100 test records including regex pattern, test string, test mode, and results. Supports one-click restore of historical tests for easy comparison of different regex solutions.
💡 Save and compare multiple regex solutions, quickly restore previous tests
Powerful Regular Expression Testing Features
Everything you need to master regular expressions
Real-time Pattern Matching
Test regex patterns instantly with live highlighting and match details as you type
Pattern Explanation Engine
Understand complex regex patterns with detailed breakdowns and plain English explanations
Performance Analysis
Detect catastrophic backtracking and performance issues before deploying to production
Multi-Language Code Generation
Generate ready-to-use code snippets for JavaScript, Python, Java, PHP, and more
Template Library
Start with proven patterns for email, phone, URL validation and common text processing
Batch Testing
Test your regex against multiple strings or upload files for comprehensive validation
Advanced Regex Features
Support for all regex flags, named groups, lookaheads, lookbehinds, and Unicode
Privacy Protected
All regex testing happens in your browser - no patterns or data sent to servers
Common Use Cases
How developers use our regex tester in real projects
Create and test input validation patterns for forms and user interfaces
Example Pattern:
Email validation: ^[\w._%+-]+@[\w.-]+\.[A-Za-z]{2,}$Extract specific data from logs, CSV files, and unstructured text
Example Pattern:
Extract phone numbers: \(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})Clean and format text data, remove unwanted characters, normalize whitespace
Example Pattern:
Remove extra whitespace: \s{2,} → single spaceCreate URL patterns for web frameworks and API routing systems
Example Pattern:
API route: /api/users/([0-9]+)/posts/([a-zA-Z0-9-]+)Parse server logs, extract error messages, and analyze system events
Example Pattern:
Extract log level: \[(DEBUG|INFO|WARN|ERROR)\]Powerful find and replace operations in code editors and text processing
Example Pattern:
Convert camelCase to snake_case in variable namesWhy Choose Our Regex Tester
Advantages over other regex testing tools
Intelligent Pattern Analysis
Advanced algorithms detect performance issues, suggest optimizations, and explain complex patterns in plain English
Comprehensive Flag Support
Full support for all regex flags including sticky, unicode, and dotAll with clear explanations of their effects
Production-Ready Code Generation
Generate optimized code snippets for 8+ languages with proper error handling and best practices
Educational Focus
Learn regex through detailed explanations, examples, and guided tutorials for all skill levels
Enterprise Features
Batch testing, performance analysis, and export capabilities suitable for professional development workflows
Modern Interface
Responsive design with syntax highlighting, live previews, and intuitive controls optimized for productivity
Frequently Asked Questions
How to Use the Regex Tester
Master regular expressions with our step-by-step guide
Enter Your Regex Pattern
Type your regular expression pattern in the pattern field. Start with simple patterns like 'hello' or use our template library for common patterns like email validation.
Configure Flags and Mode
Select appropriate flags (global, case-insensitive, etc.) and choose your test mode. Use 'match' mode to see all matches, 'replace' to substitute text, or 'test' for boolean results.
Add Test Text
Enter or paste text to test your pattern against. You can test multiple lines of text or use our batch testing feature for testing multiple strings.
Analyze Results
Review the matches, examine capture groups, and check the execution time. Use the explanation feature to understand how your pattern works.
Generate and Export Code
Generate code snippets for your programming language, export results, or save patterns to your history for future reference.
Professional Tool for Mastering Regular Expressions
Our regex tester provides enterprise-grade features and educational resources to help developers grow from beginners to regex experts. Whether you're validating user input, parsing log files, or performing complex text processing, this tool meets your professional needs.
Common Regular Expression Patterns
Most practical regex collection for development
Email Validation
^[\\w._%+-]+@[\\w.-]+\\.[A-Za-z]{2,}$Validate standard email address format
Phone Number
^1[3-9]\\d{9}$Chinese mobile phone number format validation
URL Link
https?://[\\w.-]+\\.[A-Za-z]{2,}[/\\w.-]*HTTP and HTTPS URL matching
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