Regex Tester
Test regular expressions against any text with live match highlighting.
How it works
Enter your regular expression pattern in the top field and your test string below. All matches are highlighted in real time as you type. Supports JavaScript regex flags (global, case-insensitive, multiline) and shows match groups separately.
Why use this tool?
Every developer needs a fast, reliable regex tester for validating email addresses, parsing log files, extracting data from strings, and writing form validation rules. No setup required — works instantly in the browser.
Frequently Asked Questions
What is a regular expression?
A regex (regular expression) is a pattern used to match text. For example, \d+ matches one or more digits, [A-Z] matches any uppercase letter, and ^hello matches strings that start with 'hello'.
What are common regex use cases?
Validating email addresses, phone numbers, and passwords; extracting data from log files and HTML; find-and-replace in text editors; URL routing in web frameworks; form validation in JavaScript.
What flags are supported?
g (global — find all matches), i (case-insensitive), m (multiline — ^ and $ match line starts/ends), s (dotAll — dot matches newlines), and u (Unicode mode).
Is this free?
Yes, completely free. Test regex patterns with live match highlighting in your browser.
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