Built by Switch Labs
Regular Expression Tester
Test and debug regular expressions online. Real-time matching, capture groups, explanations, and a library of common regex patterns. Supports JavaScript regex flavor.
- Real-time matching
- Capture groups
- Pattern explanations
- Common patterns
Enter text to test your regex pattern. Matches will be highlighted below.
Matches Highlighted
Matched text is highlighted. Click on matches below to see capture groups.
Match Details
All matches with their positions and capture groups.
Pattern Explanation
What your regex pattern means in plain English.
- \b - Word boundary
- + - 1 or more times
- [...] - Character set (matches any character inside)
Code Generation
Generate code for your regex in various programming languages.
const regex = new RegExp("\\b[A-Z][a-z]+\\b", "g");
const text = "The Quick Brown Fox jumps over the lazy dog.\nJavaScript is Amazing!\nTesting Regular Expressions is fun.";
const matches = text.match(regex);How to Use This Regex Tester
Regular expressions (regex) are powerful patterns used to match character combinations in strings. Our regex tester helps you build, test, and debug your patterns in real-time with instant visual feedback.
1. Enter Your Pattern
Type your regex pattern in the pattern field. Use the flag buttons to enable global, case-insensitive, multiline, and other matching modes.
2. Add Test Text
Enter or paste the text you want to test against your pattern. Matches will be highlighted in real-time.
3. View Results
See all matches, their positions, and capture groups. Use the explanation panel to understand what your pattern does.
4. Generate Code
Copy ready-to-use code in JavaScript, Python, PHP, Java, or C# to integrate your regex into your project.
Common Regex Patterns
Our pattern library includes ready-made regex for common use cases like email validation, phone numbers, URLs, dates, and more. Click the "Patterns" button to browse and load them instantly.
Regex Tutorial for Beginners
Basic Matching
Literal characters match themselves. For example, cat matches the word "cat".
Character Classes
Use \d for digits, \w for word characters, and \s for whitespace.
Quantifiers
Control how many times a pattern repeats: + (one or more), * (zero or more), ? (optional).
Capture Groups
Wrap patterns in parentheses (...) to capture matched text for later use or replacement.