Regex Tester | Regular Expression Tester Tool | SkyConverterTools

Test and debug regular expressions with real-time highlighting, capture group extraction, and comprehensive match analysis. Supports JavaScript, Python, and PHP regex flavors.

Regex Pattern

Regex Flavor

Regular Expression

Enter regex pattern with delimiters (e.g., /pattern/flags)

Regex Flags

g (Global)

Find all matches

i (Ignore Case)

Case insensitive

m (Multiline)

^/$ match line boundaries

s (Dot All)

. matches newline

u (Unicode)

Full Unicode support

y (Sticky)

Matches from lastIndex

Test String

Testing Options

Match Limit

Timeout (ms)

Highlight Matches Show Capture Groups

Common Patterns

Regex Quick Reference

Character Classes

\d Digit (0-9)

\w Word character

\s Whitespace

Quantifiers

* 0 or more

+ 1 or more

? 0 or 1

Test Results

Regex Analysis

Pattern

Matches Found

Groups Found

Processing Time

Regex Error

Highlighted Matches

Matches List

Capture Groups

No Test Results Yet

Enter a regex pattern and test string, then click "Test Regex" to see results here.

Regex Best Practices

Test Incrementally: Build and test your regex pattern step by step
Use Anchors: Use ^ and $ to match start/end of string when needed
Be Specific: Use character classes [a-z] instead of . when possible
Avoid Catastrophic Backtracking: Use atomic groups or possessive quantifiers
Comment Complex Patterns: Use (?#comment) or x flag for readability

About Regex Tester

Our Regex Tester is a comprehensive tool for developing, testing, and debugging regular expressions across multiple programming languages. Regular expressions are powerful pattern-matching tools used for text processing, validation, search, and data extraction.

The tester provides real-time highlighting, detailed match analysis, capture group extraction, and comprehensive debugging features. It supports JavaScript, Python, and PHP regex flavors with full flag support and timeout protection against catastrophic backtracking.

Perfect for developers, system administrators, data analysts, and anyone working with text processing. Whether you're validating user input, parsing log files, or extracting data from documents, this tool helps you write and test regex patterns efficiently.

How to Use

Select the regex flavor: JavaScript (browser), Python, or PHP.
Enter your regex pattern with appropriate delimiters and flags.
Configure regex flags like global, case-insensitive, or multiline.
Enter test text in the test string area or use example patterns.
Click "Test Regex" to execute the pattern against the test string.
Review matches, capture groups, and highlighted results.
Debug any errors and refine your pattern using the analysis tools.

Pro Tip: Start with simple patterns and gradually add complexity. Use the timeout setting to prevent browser hangs from complex patterns. Test with various edge cases to ensure your regex handles all scenarios correctly.