Regex Tester & Debugger
Test regular expression patterns against sample text with instant syntax checking and match highlights.
Free Online Regular Expression (Regex) Tester
ToolVixo’s Regex Tester & Debugger is a lightweight, fast, client-side utility designed to evaluate JavaScript-compatible regular expressions. Whether you need to validate email addresses, format phone numbers, extract URLs, or parse unstructured logs, our tool gives immediate visual match feedback without sending any data to external servers.
Key Features
- Real-time regex syntax execution and validation
- Instant visual match highlighting inside your sample text
- Full support for JavaScript RegEx flags (g, i, m, s)
- Extract matched strings directly into a copyable list
- 100% private client-side browser evaluation
- Free tool with zero registration requirements
Common Regex Examples
Email Address: [a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,6}
URL Match: https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_\+.~#?&//=]*)
Digits Only: \d+
IPv4 Address: \b(?:[0-9]{1,3}\.){3}[0-9]{1,3}\b
Frequently Asked Questions
What regular expression engine does this tool use?
It uses the native JavaScript standard (ECMAScript) RegExp engine directly inside your web browser.
What do the regex flags mean?
g stands for global match (find all occurrences), i for case-insensitive matching, m for multi-line matching, and s allows the dot operator to match newline characters.
Is my test text secure?
Yes, all regex testing is conducted entirely in your browser memory. No inputs or test texts leave your browser.