IsItAI 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
IsItAI
UK, 2024UK-built AI detection that gives you a confidence score, not a verdict.
- Pricing
- From £4.99/month
- Free tier
- 5 scans/day free
- 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 | IsItAI | Crossplag |
|---|---|---|
| Free tier | 5 scans/day free | Free signup with limited checks |
| Starting price | From £4.99/month | From $7/month |
| Cost per 1k words | £0.05 (Pro plan equivalent) | $0.07 |
| API available | Yes | Yes |
| Languages supported | 30 | 100 |
| Founded | 2024 | 2017 |
| Country | UK | Albania |
| Primary audience | Educators, recruiters and content teams | Universities outside the US |
| Best for | Teachers, students and recruiters who want a clear confidence score and source-passage highlighting | Universities outside the US needing multilingual coverage |
| Known weakness | Smaller brand than US incumbents | AI detection accuracy lags peers and the primary product is plagiarism |
How each tool works
IsItAI
Method: Multi-model ensemble. Combines several open detectors and weights agreement. Returns a confidence band rather than a binary verdict.
Data handling: GDPR compliant. UK and EU hosted. Submitted text is not stored after the scan completes.
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 IsItAI 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 IsItAI and Crossplag are vulnerable to this.
Where IsItAI wins
- Built for educators, recruiters and content teams.
- Method: Multi-model ensemble. Combines several open detectors and weights agreement. Returns a confidence band rather than a binary verdict.
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, IsItAI or Crossplag?
IsItAI suits teachers, students and recruiters who want a clear confidence score and source-passage highlighting. 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 IsItAI free?
5 scans/day free
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, IsItAI or Crossplag?
IsItAI suits teachers, students and recruiters who want a clear confidence score and source-passage highlighting. 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.
Try IsItAI free
5 free scans a day. No credit card. UK hosted and GDPR compliant.
Sources and further reading
- IsItAI homepage
- Pricing
- How it works
- 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?