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Regex Tester

Test regular expressions in real-time with live match highlighting, capture groups, replace preview, code generation, and pattern library — all securely in your browser.

✦ Real-Time Matching ✦ Capture Groups ✦ Code Generator ✦ Error Detection
📝 Pattern
/ g
⚠️
📋 Test String 0 chars
🔍 Results 0 matches
🔍
Enter a pattern and test string to see matches
Matches 0
Groups 0
Time 0ms
Test Length 0chars
Pattern Length 0chars
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        How It Works
        
Test Regex in 4 Simple Steps

        
No signup, no server. Just type your regex and see results instantly.

        

          

            
1

            
Enter Pattern

            
Type or paste your regex pattern in the pattern input field.

          

          

            
2

            
Add Test String

            
Enter the text you want to match against.

          

          

            
3

            
Set Flags

            
Toggle regex flags: global, case-insensitive, multiline, dotall, unicode.

          

          

            
4

            
View Results

            
See highlighted matches, capture groups, use replace, or generate code.

          

        

      

    


    


    
    

      

        Features
        
Everything You Need for Regex Testing

        
Professional-grade regex testing with powerful features for developers.

        

          

            
⚡

            
Real-Time Matching

            
See matches highlighted instantly as you type. No need to click a button — results update in real-time with debounced processing.

          

          

            
🎨

            
Capture Groups

            
View all captured groups with color coding. Named groups are displayed with their names for easy reference.

          

          

            
🔄

            
Find & Replace

            
Test replacements with capture group references ($1, $2, ${name}). See a live preview of the replaced text.

          

          

            
💡

            
Regex Explanation

            
Get a human-readable breakdown of your regex pattern. Understand every token, quantifier, and anchor.

          

          

            
💻

            
Code Generator

            
Generate ready-to-use regex code in JavaScript, Python, PHP, Java, C#, Go, and Rust.

          

          

            
📚

            
Pattern Library

            
Quick-load common regex patterns for emails, URLs, phone numbers, IP addresses, and more.

          

          

            
💾

            
Save & Export

            
Save test cases to localStorage, export as JSON, import sessions, and share via URL.

          

          

            
⚠️

            
Error Detection

            
Instantly see regex errors with position pinpointing and suggested fixes for common mistakes.

          

          

            
🔒

            
100% Private

            
All processing happens in your browser. No data is ever sent to any server.

          

        

      

    


    


    
    

      

        FAQ
        
Frequently Asked Questions

        

          

            
            
A regular expression (regex) is a sequence of characters that defines a search pattern. It is used for string matching, validation, search-and-replace, and text parsing. Regex is supported in virtually every programming language.

          

          

            
            
This tool uses the browser's built-in JavaScript regex engine (ECMAScript standard). The code generator provides equivalent patterns and usage examples for Python, PHP, Java, C#, Go, and Rust. Note that some advanced features may differ between engines.

          

          

            
            
g (global) — Find all matches instead of stopping at the first.
i (case-insensitive) — Match both upper and lower case letters.
m (multiline) — Make ^ and $ match the start/end of each line.
s (dotall) — Make . match newline characters too.
u (unicode) — Enable full Unicode matching support.

          

          

            
            
Capture groups are parts of your pattern enclosed in parentheses. Each group captures the text matched by that part of the pattern. Use (?<name>...) for named groups. In replace, reference them with $1, $2, etc., or ${name} for named groups.

          

          

            
            
Yes! Use the Save button to store test cases in your browser's localStorage. Each saved case includes the pattern, flags, and test string. You can also export all saved cases as JSON, import them later, or share a regex via URL using the hash parameter.

          

          

            
            
Click the Share button to encode your current pattern and flags into the URL hash. Anyone opening that URL will see your regex pre-loaded. This works for sharing patterns without needing to save or export files.

          

          

            
            
Absolutely. All regex testing happens entirely in your browser. No data is ever sent to any server. Your test strings and patterns remain completely private. Saved data is stored only in your browser's localStorage.

          

          

            
            
Enter your regex pattern and flags, then open the Code Generator panel. Select a programming language to see ready-to-use code snippets that implement your regex with proper syntax for that language, including match and replace examples.

          

        

      

    


    
    
  


  
  

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