How this compares with the tools you already know
What each tool costs, what it caps, and what it claims, with the source of every figure named. Where a vendor publishes an accuracy number it is recorded as their claim and kept out of any column of ours, because theirs is measured on a corpus nobody outside the vendor can see.
- A separate calibration for every language we publish, never one threshold translated across languages.
- The false positive rate is measured on writing by non-native speakers, the half the published detectors get wrong, and it is on the accuracy page.
- A reading carries our confidence rating and a mark on every sentence, and it is never presented as a verdict.
- Where the detector is weaker, on older model generations and on very short text, the accuracy page says so.
All comparisons
| Tool | Free | Paid from | Plagiarism check |
|---|---|---|---|
| This site | |||
| Blurwrite | One run a day on each tool, on the first words of the text, with no card. | 6.99 USD a month billed yearly, or 9.99 USD monthly, for 10,000 humanizer and 10,000 paraphraser words a month, and 50,000 AI detection words. | Coming soon |
| Originality.ai | 60 credits, three scans a day, 2,000 words a scan, renewed daily. | 14.95 US dollars a month, or 12.95 billed yearly, for 2,000 credits a month at 100 words a credit. | On paid credits: 1 credit per 100 words, 2 credits per 100 words for AI and plagiarism together. Checks web content through Google search. |
| GPTZero | Reported as 10,000 words a month and 10,000 characters a scan, with an account and no card. | Reported from 14.99 US dollars a month, or 8.33 billed yearly, for 150,000 words a month. | A free plan covers up to 10,000 words a month, paid plans raise the limit. Checks websites and over 100 million scholarly articles and books. |
| Copyleaks | No standing free tier reported; credits are bought. | Reported at 16.99 US dollars a month, or 13.99 billed yearly, for 100 credits at 250 words a credit. | Reported as credit based, 1 credit per 250 words. Checks the web, academic journals and shared or private data hubs. |
| Undetectable.ai | A 250-word trial. | 9.99 US dollars a month for 10,000 words, or 5.00 billed yearly. | Not compared |
| Turnitin | None. Access is through an institution. | No retail price. Reported at roughly 0.41 to 0.48 US dollars per student per year as an institutional add-on. | Sold to institutions through sales. Compares work with its repository of student papers, web pages and premium publications. |
| Grammarly | The free tier covers writing suggestions, not detection. | Reported at 12 US dollars per member a month billed yearly, or 30 a month monthly. | A free scan on the checker page, the full check on paid plans. Checks over 16 billion web pages and ProQuest academic databases. |