Regex Tester
Test regular expressions against sample text with live match highlighting, flag support, capture group output, and error feedback for faster debugging and pattern design.
How to Use the Regex Tester
- Enter your regular expression pattern in the regex field.
- Turn flags like global, case-insensitive, or multiline on or off as needed.
- Paste sample text into the test area and click test regex.
- Review highlighted matches, match totals, and capture groups to debug your pattern.
What Is Regex?
Regex, short for regular expression, is a text pattern language used to search, validate, extract, and transform strings in programming, automation, and data processing.
Common regex patterns
Developers often use regex for email matching, phone number patterns, slug cleanup, whitespace removal, token extraction, log parsing, and input validation across forms and APIs.
How to test regex
A regex tester lets you try a pattern against sample text safely before adding it to code. This makes it easier to catch bad escaping, overmatching, missing flags, and incorrect capture groups.
Regex use cases in programming
Regex is widely used in web development, CLI tools, search features, ETL jobs, validation rules, and content processing. A live tester is especially helpful when patterns become complex.
Frequently Asked Questions
What is regex?
A pattern used to match text.
How do I test regex?
Enter pattern and test text.
Is this tool free?
Yes.
Can I see matches?
Yes, highlighted in real-time.