Best AI tools to check document plagiarism
| Tool | What it does | Pricing | Free tier | Refunds |
|---|---|---|---|---|
| Scribbr | A platform offering academic proofreading, plagiarism detection, citation generation, and various AI-based writing and editing tools. | Free tier | Yes | — |
| Copyleaks | An AI-powered content analysis platform for plagiarism detection, AI content detection, and content governance. | Free tier; paid from $13.99/mo * | Yes | 10 days |
| Originality.ai | AI detection, plagiarism checking, fact checking, readability, and grammar checking tools for content integrity. | Free tier; paid from $12.95/mo * | Yes | — |
| GPTinf | An all-in-one AI writing toolkit for detecting, humanizing, paraphrasing, and checking the grammar of text content. | Free tier; paid from $4.99/mo * | Yes | — |
| Paperpal | Integrated AI workspace for academic writing and submission preparation for researchers. | Free tier * | Yes | — |
— means the vendor does not state it on the pages we read.
* pricing not verified against the vendor's pricing page.
Scribbr
Visit Scribbrscribbr.com
A platform offering academic proofreading, plagiarism detection, citation generation, and various AI-based writing and editing tools.
Detect and resolve unintentional plagiarism with the Scribbr Plagiarism Checker, so you can submit your paper with confidence.
Pricing, in their words: “We believe that every student should have the right tools for academic success. Free tools like a paraphrasing tool, AI Humanizer, grammar checker, summarizer and an AI Proofreader.” (pricing)
Subscription terms they state: cancel by email (source)
Limits the vendor states:
- The Document must be education related.
- Cannot cancel Plagiarism, Citation, Self-Plagiarism, or AI proofreader checks.
Copyleaks
Visit Copyleakscopyleaks.comAn AI-powered content analysis platform for plagiarism detection, AI content detection, and content governance.
Copyleaks scans AI-generated text and checks for potential plagiarism in a single report.
Pricing: Free tier; paid from $13.99/mo (pricing)
Subscription terms they state: cancel in-app · auto-renews · 10-day refund window (source)
Limits the vendor states:
- Cannot check for image plagiarism
Originality.ai
Visit Originality.aioriginality.ai
AI detection, plagiarism checking, fact checking, readability, and grammar checking tools for content integrity.
A modern, Al-powered plagiarism checker that is more accurate than Grammarly & Copyscape.
Pricing: Free tier; paid from $12.95/mo (pricing)
Subscription terms they state: cancel in-app · auto-renews (source)
No usage limits stated on the pages we read.
GPTinf
Visit GPTinfgptinf.comAn all-in-one AI writing toolkit for detecting, humanizing, paraphrasing, and checking the grammar of text content.
Check for plagiarism against all web sources available.
Pricing: Free tier; paid from $4.99/mo (pricing)
Subscription terms they state: cancel in-app (source)
No usage limits stated on the pages we read.
Paperpal
Visit Paperpalpaperpal.com
Integrated AI workspace for academic writing and submission preparation for researchers.
精准查重，通过可信赖的相似度检测，助你降低论文被初审拒稿的风险
Pricing: Free tier (pricing)
No usage limits stated on the pages we read.
FAQ
Is there a free tool to check document plagiarism?
Yes — Scribbr, Copyleaks, Originality.ai, GPTinf, Paperpal offer a free tier.
What is the cheapest paid option to check document plagiarism?
GPTinf starts at $4.99/month.
Which of these have an API?
Scribbr, Copyleaks, Originality.ai document a developer API.
How do I cancel these subscriptions?
Scribbr: cancel by email; Copyleaks: cancel in-app; Originality.ai: cancel in-app; GPTinf: cancel in-app. Paperpal does not state a cancellation route on the pages we read.
Can I get a refund?
Copyleaks states a 10-day refund window. The others (Scribbr, Originality.ai, GPTinf, Paperpal) do not state a refund policy on the pages we read.
Do these subscriptions auto-renew?
Copyleaks, Originality.ai state that paid plans renew automatically. Check the billing page before subscribing; the rest do not state it either way.
Sources
Every fact above was read from the vendors' own pages: