Find & replace

In plain mode the search text is escaped, so characters like . and ( match themselves rather than being treated as regular-expression syntax. Tick “regular expression” to use the full pattern language.

Whole words

The whole-word option wraps your pattern in word boundaries, so searching for “cat” will not match “catalogue”. A word boundary sits between a word character and a non-word character — which means it does not do what you want for terms containing hyphens or apostrophes.

Useful patterns

\s+

Any run of whitespace — replace with a single space to normalise.

^\s+|\s+$

Leading and trailing whitespace on each line (needs multiline in a full engine).

(\w+)@(\w+)

Two capture groups, reusable as $1 and $2.

[^\x20-\x7E]

Anything outside printable ASCII — good for finding stray characters.

Everything stays local

The replacement runs in your browser. Nothing is uploaded, which matters when the text you are cleaning up contains anything sensitive.