How to use it
Paste your text in the first box, type what you want to find and what to replace it with, and the result appears below straight away, with a count of how many places changed and a few examples. By default every match is replaced, capital letters don’t matter, and the search text is taken literally, so a dot is just a dot. Tick Match case to tell “Cat” from “cat”, and Whole words only to change “cat” without touching “concatenate”. Leave Replace with empty to delete every match. Use Use the result as the new text to chain several replacements one after another.
Regular expressions
Tick Regular expression to use patterns. For example, \d+ finds any run of digits, ^\s+|\s+$ finds spaces at the start or end of each line, and (\w+)@(\w+)\.com finds addresses. In the replacement you can use $1, $2 and so on to put back the parts you captured in brackets, so (\d+)-(\d+)-(\d+) with $3/$2/$1 turns 2026-10-18 into 18/10/2026. ^ and $ match at the start and end of every line. If your pattern isn’t valid, the tool says what is wrong instead of changing anything.
Questions
Is there a size limit? Text up to 500,000 characters. Is my text uploaded? No, the work is done in your browser. Why do I see a dollar sign in my result? In normal mode $ in the replacement is just a dollar sign; it only means a captured group when Regular expression is ticked. Can I test a pattern on its own? Yes, use the Regex Tester; for tidying text try Text Cleanup Tools.