Text copied from a web page, document, or email brings more than the words. Here is what comes along, how to remove it with what's built into macOS, and where PlainType fits.
" and '. They
read well in prose and get in the way where straight quotes are
expected, like code, terminal commands, and data files.
Open System Settings › Keyboard, go to Text Input, click Edit, and turn off Use smart quotes and dashes. This only changes what happens while you type. Text you copy from somewhere else keeps its curly quotes.
Use Find and Replace in your editor. Search for each curly character
— “, ”, ‘, and ’ — and replace it
with a straight " or '. That's four passes
per document.
The Substitutions panel in Apple's apps (Edit › Substitutions › Show Substitutions) goes the other way: it applies smart quotes to existing text. It won't straighten them.
Paste with ⌥⇧⌘V (Paste and Match Style) to leave fonts and colors behind. It doesn't change the characters, so smart quotes and Markdown symbols still come through. More on pasting without formatting.
PlainType does all of this in one step. It strips formatting, hidden markup, smart quotes, common Markdown artifacts, and stray whitespace from copied text, so what you paste is plain text that drops cleanly into notes, docs, chat, email, and task trackers.
To see it work, copy formatted text from a web page or rich-text editor and paste it into a plain text field.
PlainType is a native Mac app for macOS 14 Sonoma or later. See how it works.
Related: How to paste without formatting on a Mac