A regex tester is an online tool that allows you to test and validate regular expressions (regex) against sample text. It helps developers and data analysts verify that their regex patterns work correctly before implementing them in code.

Our free regex tester provides real-time feedback, showing matches, groups, and capture details as you type. It supports all common regex flags and provides detailed information about each match found in your test string.

• Real-time regex testing with instant feedback

• Support for all regex flags (global, ignore case, multiline, etc.)

• Detailed match information including position and groups

• Syntax highlighting for matched text

• Named capture groups support

• Error detection and validation

• Copy and share functionality

• Quick regex reference guide

1. Enter your regular expression pattern in the regex input field

2. Select appropriate flags (global, ignore case, multiline, etc.)

3. Input your test string in the text area

4. View real-time results with highlighted matches

5. Examine detailed match information including groups and positions

6. Use the reference guide for common regex patterns

7. Copy your regex or share a link to your test

• Email validation: \b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b

• Phone numbers: \+?[1-9]\d{1,14}

• URLs: https?://[\w\-\.]+\.[a-z]{2,}[/\w\-\._~:/?#\[\]@!\$&'\(\)\*\+,;=]*

• Dates (YYYY-MM-DD): \d{4}-\d{2}-\d{2}

• IP addresses: \b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b

• Credit card numbers: \d{4}[\s-]?\d{4}[\s-]?\d{4}[\s-]?\d{4}

• Global (g): Finds all matches instead of stopping after the first

• Ignore Case (i): Makes the pattern case-insensitive

• Multiline (m): ^ and $ match start/end of each line, not just string

• Dot All (s): Makes . match newline characters

• Unicode (u): Enables full Unicode support

• Sticky (y): Matches only from the index indicated by lastIndex

• Free and no registration required

• Works entirely in your browser - no data sent to servers

• Real-time testing and validation

• Comprehensive match details and debugging info

• Built-in regex reference for learning

• Copy and share functionality for collaboration

• Mobile-friendly responsive design

• Fast and lightweight interface