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Regex Tester

Test and debug your regular expressions online in real time. Enter a pattern, paste your test text, and instantly see all matches highlighted.

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                        Enter a regex pattern above to start matching.
                    

                

            


        
    


        


        

            

                What is a Regular Expression?
            

            

                A regular expression (regex) is a sequence of characters that defines a search pattern. It is used to find, match, extract, or replace text that meets specific criteria. Regex is supported in virtually all programming languages and text editors, making it a fundamental skill for developers, data analysts, and anyone working with text data.

            

        


        

            

                Understanding Regex Flags
            

            
    
                                    
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                        g
                        Global — finds all matches instead of stopping at the first one.
                    
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                        i
                        Case insensitive — matches uppercase and lowercase letters interchangeably.
                    
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                        m
                        Multiline — makes ^ match the start of each line and $ the end of each line.
                    
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                        s
                        Dot All — allows the dot (.) to match newline characters as well.
                    
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                        u
                        Unicode — enables full Unicode support for patterns matching emojis and special characters.
                    
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                Common Uses of Regular Expressions
            

            
    
                
  • Validate input formats such as email addresses, phone numbers, or postal codes.
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  • Extract data from structured or semi-structured text (logs, CSV, HTML snippets).
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  • Find and replace patterns in code editors, scripts, or text files.
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  • Parse URLs, query strings, or file paths programmatically.
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                Good to know
            

            

                This tool runs entirely in your browser using JavaScript's native RegExp engine. No data is sent to any server. The regex syntax follows the ECMAScript / JavaScript standard, which is compatible with most modern programming languages and tools.