Regex Tester & Validator
Test and validate regular expressions with real-time matching, highlighting, and detailed match results. Supports all regex flags and common patterns. 100% client-side, no uploads required.
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Frequently Asked Questions
Is my data secure when using this regex tester?
Yes, absolutely. The regex testing runs entirely in your browser using client-side JavaScript. No data is uploaded to any server - everything stays on your device for maximum privacy and security.
What regex flags are supported?
We support all JavaScript regex flags: g (global), i (case-insensitive), m (multiline), s (dotall), u (unicode), and y (sticky). You can combine multiple flags together.
Can I test complex regex patterns?
Yes, the tool supports all JavaScript regex features including groups, lookaheads, lookbehinds, quantifiers, character classes, and more. It works exactly like JavaScript's RegExp object.
How does the match highlighting work?
The tool highlights all matches in real-time as you type. Matched text is highlighted in pink, making it easy to see which parts of your test string match the pattern.
What are the common patterns library?
We include pre-built patterns for email validation, URLs, phone numbers, dates, IP addresses, credit cards, hex colors, and more. Click 'Common Regex Patterns' to browse and insert them.
Can I save my regex patterns?
Yes! Patterns and test strings are automatically saved to your browser's localStorage. You can also share patterns via URL - just copy the URL after entering your pattern and test string, and anyone who opens that URL will see your exact setup.