Regex Tester
Test regular expressions, inspect matches, and validate regex patterns instantly in your browser with visual highlighting and capture group display.
Results
Enter a pattern and test text, then click Test
What is Regular Expression Testing?
Regular expressions (regex) are powerful patterns used for matching and manipulating text. They are essential tools for developers working with validation, parsing, search-and-replace operations, and data extraction. A regex tester helps you develop and debug these patterns by showing exactly what text matches your expression and why.
Common use cases include validating email addresses, phone numbers, and URLs, extracting data from log files and structured text, parsing configuration files and code, cleaning and transforming text data, and implementing search functionality. This tool provides real-time feedback with visual highlighting, making it easy to understand how your pattern behaves and identify issues.
The Regex Tester supports standard JavaScript regex flags: the global flag (g) finds all matches instead of stopping after the first, the case-insensitive flag (i) ignores letter case when matching, and the multiline flag (m) treats beginning and end characters (^ and $) as working per line instead of per string. Use this tool to build confidence in your regex patterns before deploying them to production code.