- Is this Regex Tester free to use?
- Yes, our Regex Tester is completely free with no usage limits. Test and debug as many regular expressions as you need without any registration or restrictions.
- Is my data private when testing regex patterns?
- Yes, all regex testing happens locally in your browser using JavaScript's native RegExp engine. Your test strings and patterns are never sent to any server. This is especially important when testing patterns against sensitive data like emails, phone numbers, or personal information.
- What regex flavor does this tool use?
- This tool uses JavaScript's built-in regular expression engine, which is based on ECMAScript standards. It supports common features like character classes, quantifiers, groups, lookahead, and Unicode. Some advanced features available in other regex flavors (like lookbehind in older browsers or atomic groups) may have limited support.
- What do the different regex flags mean?
- The global (g) flag finds all matches instead of stopping at the first. Case insensitive (i) ignores letter case when matching. Multiline (m) makes ^ and $ match line starts and ends, not just string boundaries. Dot-all (s) makes the dot (.) match newline characters as well.
- How do I match special characters in regex?
- Special regex characters like . * + ? ^ $ { } [ ] \ | ( ) need to be escaped with a backslash when you want to match them literally. For example, to match a period, use \. instead of just a dot. To match a backslash itself, use \\.