ToolsRegEx Tester
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Test, debug, and validate JavaScript, PHP (PCRE), and Python regular expressions in real-time with match highlighting, capture groups, and flag selectors.
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Tokens, code & payloads never leave your browser.
Zero Latency Execution
Instant processing via native browser Web APIs.
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Unlimited, free access without paywalls or quotas.
Type your pattern and select the required flags (e.g. /^[a-zA-Z0-9]+$/gi).
Paste your sample strings, logs, or code into the test input area.
View highlighted matches and captured group values in the results panel.
Build and verify strict regex patterns for email validation, strong passwords, slugs, and international phone numbers.
// Email Validation Regex Pattern
const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;
// Testing:
emailRegex.test('[email protected]'); // true
emailRegex.test('invalid-email@'); // falseExtract IP addresses, HTTP status codes, and timestamps from server access logs using named or numbered capture groups.
This tester uses the native ECMAScript (JavaScript) RegEx engine, which supports lookahead, lookbehind, named capture groups, and standard PCRE-compatible syntax.
Without the "g" flag, the regex engine stops after finding the first match. With "g" enabled, it finds every occurrence of the pattern across the entire test string.
Learn engineering best practices, design patterns, and code architecture related to this tool.