Paste as Plain Text
To automatically remove formatting from every item you copy, check the “Always paste as Plain Text” option in Paste Settings → General.
To paste one particular item as plain text, open Paste with Shift-Command-V, select the item, and press Shift-Return — or right-click the item and select “Paste as Plain Text” in the context menu.
Shift-Return works on the item you have selected in the Paste window, so press it there rather than in the app you are pasting into. On its own in a text field it does whatever that field normally does, such as adding a line break.
You can change the Plain Text modifier in Paste Settings → Shortcuts, in the Plain Text mode row. It is a modifier key rather than a full shortcut, so the choice is a single key — Command, Shift, Control, or Option — held while you press Return.
Please note that Paste does not modify your existing clipboard content automatically — you’ll need to paste items from your current clipboard if you want to remove formatting from them.