Help:VisualEditor/User guide/Find and replace

VisualEditor includes a powerful Find and Replace tool. After loading a page in VisualEditor, you can access it from Menu icon, then choosing. You can also press G or Cmd.

Regular expressions
Switch on button, to enable regular expressions (regex).

In the field, some special characters are interpreted as PCRE metacharacters. [ https://www.php.net/manual/regexp.reference.meta.php See documentation].

If you capture subpattern using parentheses, you may reuse captured string in field with ordered  variables.

Limitations
You cannot look for newline character.

You cannot replace a phrase based on a lookahead or lookbehind regex.