Regex Tester
An online tool to test regular expression patterns in real-time with match highlighting.
How to Use the Regex Tester
Enter a regular expression pattern and test text. Matches are highlighted in real-time as you type. You can set flags (g for global, i for case-insensitive, m for multiline, etc.) to customize matching behavior. Match results show matched text, groups, and positions. This tool is useful for developing and debugging regular expressions for any programming language.
About Regular Expressions
Regular expressions (regex) are patterns used to match character combinations in strings. They are a powerful tool used across virtually all programming languages for text search, validation, extraction, and replacement. Common use cases include email validation, URL parsing, log file analysis, and data extraction. While regex syntax can be complex, mastering it significantly improves text processing efficiency.
Frequently Asked Questions (FAQ)
Q. What regex flags are supported?
A. The tool supports standard JavaScript regex flags: g (global), i (case-insensitive), m (multiline), s (dotAll), and u (unicode).
Q. Can I see capture groups?
A. Yes, matched groups are displayed with their index and content, making it easy to verify capture group patterns.
Q. Is my input data safe?
A. All processing is completed within your browser. Input data is never sent to any server.