What is a regex tester?

A regex tester is a tool that tests and debugs regular expressions in real-time. It helps developers validate pattern matching, test different inputs, and understand how regex patterns work. Our free online tool supports JavaScript regex syntax with live matching and highlighting.

Is the regex tester free?

Yes, completely free with no registration required.

No, all processing happens locally in your browser.

Regex Tester & Debugger - Test Regular Expressions Online | DevTools Pro

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Regex Tester

Test and debug regular expressions in real-time

Regular Expression

Test String

Regex Flags

gGlobal - Find all matches

iCase insensitive

mMultiline

sDot all - . matches newlines

uUnicode

ySticky

Match Results

Enter regex and test string to see results

Highlighted Matches

Quick Examples

Regular Expression Tester

Our regex tester is an essential tool for developers who need to create, test, and debug regular expressions. Perfect for data validation, text processing, and pattern matching, this tool provides real-time feedback and detailed explanations of your regex patterns.

Common Use Cases

•Validating email addresses and phone numbers
•Extracting data from log files and text documents
•Searching and replacing text patterns in code
•Validating user input in web forms
•Parsing structured data from unstructured text

Who Benefits from This Tool

•Software developers implementing data validation
•Data analysts processing text data
•DevOps engineers parsing log files
•Web developers creating form validation
•System administrators managing text processing

Frequently Asked Questions

What regex flavors are supported?

Our tool supports JavaScript regex syntax, which is compatible with most modern programming languages including JavaScript, Python, Java, and C#.

Can I test regex with multiple test strings?

Yes, you can test your regex pattern against multiple test strings simultaneously to ensure it works correctly across different scenarios.

Does the tool explain regex patterns?

Yes, our tool provides detailed explanations of regex patterns, helping you understand how each part of your expression works.

Is there a limit on regex pattern length?

While there's no strict limit, very complex patterns may take longer to process. The tool is optimized for typical regex patterns used in development.