Regex Tester
Test a regular expression: matches, positions and capture groups update as you type.
The regex tester checks a regular expression against your text in real time. Enter a pattern, flags (g, i, m, s, u, y) and some text, and the tool highlights every match, shows their positions, and displays the contents of capture groups, including named ones (?<name>…).
Regular expressions are powerful but finicky — it's much easier to see exactly what's matching than to guess. The tester is handy when parsing logs, validating form fields (email, phone), doing search-and-replace, or extracting data from text. You immediately see why a pattern misses what you want or grabs too much.
It uses your browser's native RegExp engine (JavaScript syntax). Everything is computed locally — neither the text nor the pattern is ever sent anywhere.