🔍 Regex Tester
Test regular expressions in real-time. See matches highlighted, capture groups, and match details.
Quick Reference
📖 Regular Expressions Guide
Regular expressions (regex) are powerful patterns for matching, searching, and manipulating text. They are supported in virtually every programming language (JavaScript, Python, Java, PHP, etc.) and are essential for data validation, text parsing, search-and-replace, and web scraping.
A regex pattern consists of literal characters and metacharacters. For example, \d+ matches one or more digits, [A-Za-z]+ matches words, and ^.+@.+\.\w{2,}$ is a basic email pattern. Mastering regex can save hours of manual text processing.
❓ Frequently Asked Questions
.* is greedy — it matches as many characters as possible. .*? is lazy — it matches as few characters as possible. In the string "abc123def", a.*d matches "abc123d" (greedy), while a.*?d would also match "abc123d" but prefers the shortest match when multiple are possible.
Escape them with a backslash: \. matches a literal dot, \( matches a parenthesis, \\ matches a backslash. Characters that need escaping: . * + ? ^ $ { } [ ] ( ) | \ /
📖 What Is a Regular Expression?
Regular expressions (regex) are powerful pattern-matching sequences used to search, validate, and transform text. They're essential for form validation, data extraction, log parsing, search-and-replace operations, and text processing in virtually every programming language.
Our regex tester provides real-time matching with visual highlighting, group capture display, and common pattern templates. Test your patterns safely in the browser without executing any server-side code.
🚀 How to Use This Tool
- Enter your regex pattern in the pattern field
- Type or paste test text in the input area
- View real-time matches highlighted in the text
- Inspect captured groups and match details
💡 Tips & Best Practices
Regex Tip: Start simple and build complexity gradually. Use \d for digits, \w for word characters, \s for whitespace. Common patterns: email validation, phone numbers, URL matching, and IP addresses.