The plagiarism checker is deactivated by default. It is currently available in the Grammarly Editor, in Microsoft Word with Grammarly for Windows and Mac, in Pages with Grammarly for Mac, and in Google Docs via the browser extension.
To learn how to activate the plagiarism checker in different product offerings, please check out this article: I can't activate the plagiarism checker
Note: If your Grammarly account is provided by your school and you do not see the Check for AI text & plagiarism option, it means your institution has opted out of using Grammarly’s plagiarism and AI text checker. This may be because your school uses another service for plagiarism checking.
If you know the plagiarism checker is supposed to be there, but you still don’t see it, you might have accidentally created and logged in to a Grammarly Free account. Please make sure to log in to your paid account to access the plagiarism checker.