Literal by default, on purpose
If you search for a.b or (test), you want those exact characters — not their regular-expression meaning, where a dot matches any character. Many online tools forget to escape your input and return nonsense. Here the search is literal by default; tick the box to switch to a regular expression when you genuinely want one.
The match counter
The number of replacements updates live. It is the best safeguard before copying: if you expected three replacements and the tool reports forty-seven, your search is too broad — usually because it also matches inside other words.
Frequently asked questions
How do I replace a whole word only?
Tick «regular expression» and wrap your word in boundaries: \bcat\b will not match «kitten».
How do I delete a word instead of replacing it?
Leave the replacement field empty: the matches are simply removed.
What if my regular expression is invalid?
The error message is shown and your text stays untouched. Nothing changes until the expression is valid.