Regex Tester
Write a regular expression and test it against any text with live match highlighting.
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About the Regex Tester
Regular expressions (regex) are powerful patterns used to search, match, and manipulate text. The ToolNook Regex Tester lets you write and test JavaScript-compatible regular expressions in real time, with live match highlighting and match details.
Regex Flags
- g — Global: find all matches (not just the first)
- i — Case-insensitive: match regardless of letter case
- m — Multiline: ^ and $ match line boundaries
- s — Dotall: dot (.) matches newline characters too
Common Use Cases
Regex testers are used for data validation (emails, phone numbers, URLs), search and replace operations in code editors, parsing log files, extracting data from text, and writing cleaner code.