Instant plagiarism check for essays and documents. Detect plagiarism, fix grammar errors, and improve your vocabulary in seconds. Log in. Plagiarism Checker by Grammarly. Grammarly’s plagiarism checker detects plagiarism in your text and checks for other writing issues. Catch plagiarism from ProQuest databases and over 16 billion web pages. Upload a file. Scan for plagiarism. Get feedback on.