Regex Tester
Test your regular expressions against text in real-time. See matches highlighted instantly as you type.
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The Regex Tester is an essential tool for developers and data analysts who work with regular expressions. It provides an interactive environment to build, test, and debug regex patterns against sample text, with real-time highlighting of all matches. This immediate feedback loop significantly speeds up the process of creating and validating complex patterns, all securely within your browser.
- Enter your regular expression pattern in the 'Pattern' input field.
- Enter any flags (like 'g' for global search or 'i' for case-insensitive) in the 'Flags' field.
- Paste the text you want to test your pattern against into the 'Test String' area.
- The 'Highlighted Matches' box will update in real-time, showing you exactly what parts of your text match the pattern. The total match count is displayed above.
What are regex flags?
Flags are optional parameters that modify the search behavior. The most common are:
- g (global): Finds all matches instead of stopping after the first one.
- i (ignore case): Makes the search case-insensitive.
- m (multiline): Allows the start (^) and end ($) anchors to match the start and end of individual lines, not just the whole string.
What syntax does this tester use?
This tool uses your browser's built-in JavaScript regular expression engine, which supports a modern, feature-rich syntax (ECMAScript).
Is my data secure?
Yes. All testing is performed on your device in your browser. Your regex patterns and test strings are never sent to our servers, ensuring complete confidentiality.