Copyleaks vs Crossplag: AI detector comparison
A side by side look at pricing, methodology, language support and best-fit use case. Every claim on this page is linked to a source at the bottom.
Last updated . Reviewed by IsItAI Editorial.
At a glance
Copyleaks
Israel, 2015Enterprise-grade detection with multilingual support.
- Pricing
- From $9.99/month (100 credits)
- Free tier
- Limited free credits
- API
- Yes
- Languages
- 30
Crossplag
Albania, 2017Multilingual plagiarism and AI detection for academic institutions.
- Pricing
- From $7/month
- Free tier
- Free signup with limited checks
- API
- Yes
- Languages
- 100
Side by side
| Feature | Copyleaks | Crossplag |
|---|---|---|
| Free tier | Limited free credits | Free signup with limited checks |
| Starting price | From $9.99/month (100 credits) | From $7/month |
| Cost per 1k words | $0.10 | $0.07 |
| API available | Yes | Yes |
| Languages supported | 30 | 100 |
| Founded | 2015 | 2017 |
| Country | Israel | Albania |
| Primary audience | Enterprises and institutions | Universities outside the US |
| Best for | Enterprise teams needing multilingual detection and integrations | Universities outside the US needing multilingual coverage |
| Known weakness | Pricier than competitors for low-volume users | AI detection accuracy lags peers and the primary product is plagiarism |
How each tool works
Copyleaks
Method: Proprietary classifier with paraphrasing-resistance claims. Integrates with LMS and CMS platforms.
Data handling: Enterprise tier offers no-storage option. Default plan stores submissions.
Crossplag
Method: AI detector layered onto the multilingual plagiarism engine.
Data handling: EU hosted. Submissions retained per academic-institution norms.
How accurate are AI detectors? What the research says
Two findings from independent academic research apply to almost every detector on this list, including Copyleaks and Crossplag.
1. False positives on non-native English writers. Liang et al. (Stanford, 2023) found that GPT detectors flagged over half of TOEFL essays written by non-native English speakers as AI-generated, while flagging almost none of the essays from US students. If your use case involves non-native English writers, never treat a detector verdict as proof on its own.
2. Paraphrasing reliably defeats classifiers. Sadasivan et al. (Maryland, 2023) showed that running AI output through a paraphraser drops detection performance close to chance. Both Copyleaks and Crossplag are vulnerable to this.
Where Copyleaks wins
- Built for enterprises and institutions.
- Method: Proprietary classifier with paraphrasing-resistance claims. Integrates with LMS and CMS platforms.
Where Crossplag wins
- Wider language support at 100 versus 30 languages.
- Built for universities outside the us.
- Method: AI detector layered onto the multilingual plagiarism engine.
Which one should you pick, Copyleaks or Crossplag?
Copyleaks suits enterprise teams needing multilingual detection and integrations. Crossplag suits universities outside the us needing multilingual coverage. Pick based on which fits your workflow. Treat any detector verdict as a screening signal, not proof.
Frequently asked questions
Is Copyleaks free?
Limited free credits
Is Crossplag free?
Free signup with limited checks
Can either tool be fooled by paraphrasing?
Yes. Sadasivan et al. (2023) demonstrated that paraphrasing reliably defeats most AI classifiers. Treat any detector verdict as a screening signal, not proof.
Are AI detectors fair to non-native English writers?
Independent research (Liang et al. 2023) found high false-positive rates for non-native English writing. Always combine a detector signal with other evidence, never use it as a sole basis for an academic or hiring decision.
Which one should I pick if I have to choose one, Copyleaks or Crossplag?
Copyleaks suits enterprise teams needing multilingual detection and integrations. Crossplag suits universities outside the us needing multilingual coverage. Pick based on which fits your workflow. Treat any detector verdict as a screening signal, not proof.
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Sources and further reading
- Copyleaks AI content detector
- Copyleaks pricing
- Crossplag AI detector
- Crossplag pricing
- Liang et al. (Stanford, 2023): GPT detectors are biased against non-native English writers
- Sadasivan et al. (2023): Can AI-generated text be reliably detected?