Originality.AI vs PlagiarismCheck.org

Originality.AI

The detector to pick if you are a publisher or agency policing freelance output at volume, because the team history and writing replay matter more than the raw score. A free Basic tier (three AI-only scans a day, 2,000 words each) now lets you test it before paying. Do not use it to accuse a student; no detector is accurate enough to carry that weight.

Pros

• +Credit model is legible: 100 words per credit, no hidden weighting
• +API on the higher tier makes batch pipelines possible
• +Chrome extension works inside Google Docs, where the writing actually happens
• +Writing replay from revision history is process evidence, not just a score
• +Free Basic tier allows three AI-only scans a day with file upload, no subscription needed

Cons

• −Monthly subscription credits expire, so a light month is wasted spend
• −The jump from $14.95 to $179 a month is a steep single step
• −False positives on heavily edited or non-native English writing are a documented hazard across every detector
• −Accuracy benchmarks are largely vendor-run

PlagiarismCheck.org

The selling point is that one submission answers both questions a teacher has — was this copied, and was this generated — instead of running two services. Ten years of operation and real LMS plugins put it ahead of the many single-page detectors that appeared in 2023. Treat the accuracy claim with the scepticism every AI detector deserves: the underlying signals are statistical and non-native writers get flagged disproportionately across this whole category.

Pros

• +Plagiarism and AI detection run on a single upload rather than two separate tools
• +Sentence-level output shows which passages triggered the score, not just a document percentage
• +Genuine LMS integrations across seven platforms, plus a Google Docs add-on and Chrome extension
• +OCR handles scanned or photographed submissions
• +Documented API for business use

Cons

• −The published '99% accuracy' figure is the vendor's own and is not independently verified
• −Institutional pricing is quote-only; the pricing page shows no numbers at all
• −No company jurisdiction is disclosed, which matters for student-data processing
• −AI detectors as a class produce false positives on formulaic and non-native writing

Is Originality.AI cheaper than PlagiarismCheck.org?

Originality.AI starts at $14.95/mo. An entry price for PlagiarismCheck.org is not confirmed by us yet, so check its pricing page before you compare.

Does Originality.AI or PlagiarismCheck.org have a free tier?

Originality.AI has a free tier; PlagiarismCheck.org has paid plans only.

Which has a public API, Originality.AI or PlagiarismCheck.org?

Both ship a public API, so either can be built on; the fact table above shows the platforms each one runs on.