What is PaperRater?
PaperRater is a longstanding free tool for students and writers that combines automated grammar and spelling correction with a plagiarism checker. Submissions are scored using PaperRater's own algorithms (nicknamed 'Grendel') for grammar, vocabulary, and writing quality, with results typically returned within 5–15 seconds and no signup required.
Its plagiarism checker compares text against more than 10 billion online documents to flag copied or closely matching passages. The free plan covers short submissions with a handful of plagiarism checks per month, while a Premium subscription raises the document length and monthly check limits and adds file upload support and faster processing.
Key features
- Grammar, spelling, and style checking with detailed error explanations
- Plagiarism checker compares text against 10+ billion online documents
- Automated essay/paper scoring based on vocabulary and writing quality
- No signup required for the free grammar and plagiarism tools
- File upload (DOC, DOCX, TXT, RTF, ODT, PDF) on the Premium plan
- Results typically returned in 5–15 seconds
How to get started
- Paste your essay or paper text into the checker (or upload a file on Premium)
- Run the grammar/style check or the plagiarism checker
- Review flagged grammar issues and any matching plagiarized text
- Revise your draft based on the suggestions
- Upgrade to Premium for longer documents and more monthly checks
PaperRater pricing
PaperRater's free plan covers submissions up to 5 pages with 50 submissions and 10 plagiarism checks per month. Premium ($14.95/month or $95.40/year) raises that to 20 pages, 200 submissions, and 25 plagiarism checks per month, adds file uploads, and removes ads.
| Plan | Price | Best for |
|---|---|---|
| Free | $0 | Short essays and occasional plagiarism checks |
| Premium | $14.95/mo ($95.40/yr) | Longer papers and more frequent plagiarism checking |
Our take: Has offered free, instant plagiarism and grammar checking with no signup for well over a decade, making it a familiar first stop for students despite newer, more specialized detectors.
Prices verified 2026-09. Plans change often — confirm on the official site above before you buy.
Use cases
- Students proofreading an essay and checking for accidental plagiarism before submission
- Teachers doing a quick originality check on student papers
- ESL writers wanting instant grammar feedback without a human editor
- Freelance writers double-checking originality before delivering client work
PaperRater vs. alternatives
| Tool | How it compares |
|---|---|
| PaperRater | Free online proofreader that checks grammar, spelling, and writing quality alongside a plagiarism scan against 10+ billion documents. |
| Grammarly | Grammarly offers deeper style and tone suggestions but bundles plagiarism checking only in its paid tiers. |
| QuillBot | QuillBot focuses more on paraphrasing and rewriting than plagiarism detection. |
| Scribbr | Scribbr's plagiarism check is priced per document rather than as a monthly subscription. |
FAQ
Is PaperRater free to use?
PaperRater's plans: Free; Premium $14.95/mo or $95.40/yr. Pricing and free-tier limits change over time, so check the official site above for the latest details.
What is PaperRater used for?
Free online proofreader that checks grammar, spelling, and writing quality alongside a plagiarism scan against 10+ billion documents.
Who is PaperRater best for?
PaperRater is a good fit for students proofreading an essay and checking for accidental plagiarism before submission, or teachers doing a quick originality check on student papers.
What are the alternatives to PaperRater?
Commonly compared alternatives include Grammarly, QuillBot, and Scribbr, see the comparison above for how they differ.
How much does PaperRater cost?
PaperRater's core grammar and plagiarism checking is free. The Premium plan costs $14.95/month or $95.40/year and raises document length, monthly submission, and plagiarism-check limits.
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QLast updated: 2026-09 · Reviewed by AIKetra editors · How we evaluate tools · Embed a Featured badge