How it works
In plain mode the text you type is matched literally — dots, brackets and question marks have no special meaning. Turn on regular expression mode to match patterns instead: \d+ for any number, ^ and $ for the start and end of each line, or (\w+)@(\w+) to capture parts you can reuse in the replacement as $1 and $2.
Whole words only stops "cat" from matching inside "category", and works with letters from any language. Case sensitive off makes "Colour", "COLOUR" and "colour" all match. Every occurrence is replaced in one pass, and the counter shows how many changes were made.
Your text is processed locally in your browser and never uploaded.
Frequently asked questions
How do I replace line breaks?
Turn on regex mode and search for \n. To join lines with a comma, replace \n with ", ". In regex mode the replacement understands \n and \t too, so replacing ", " with \n splits a comma-separated list onto separate lines.
How do I insert a literal dollar sign in regex mode?
Write $$ in the replacement. A single $ followed by a number refers to a captured group.
Which regex syntax is supported?
JavaScript regular expressions with the Unicode flag, including lookbehind, named groups (?<name>…) and Unicode property escapes like \p{L}.