PaperRed

In the browser, PaperRed checks a paper for plagiarism and AI-written text, then gives you rewriting tools to fix what gets flagged.

PaperRed is a free plagiarism checker and AI content detector geared toward students and researchers who want to review their work before submitting it.

The site says its results are comparable to the checks universities run, though you should see that as a claim rather than a guarantee.

Beyond detection, PaperRed includes an AI paraphraser for rewriting passages, plus AI-driven paper creation and formatting assistance.

That makes it closer to a small academic writing workspace than a single-purpose checker.

Pricing is listed as free, so trying a draft costs nothing.

Be careful with the paper creation feature, since turning in generated text can cause the very problems a detector looks for.