IsItAI vs Scribbr: 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
Scribbr
Netherlands, 2012 (AI detector 2023)Student-focused, integrated with Scribbr's plagiarism and citation tools.
- Pricing
- Pay-per-check from $9.95
- Free tier
- 1.2k words free
- API
- No
- Languages
- 4
Side by side
| Feature | IsItAI | Scribbr |
|---|---|---|
| Free tier | 5 scans/day free | 1.2k words free |
| Starting price | From £4.99/month | Pay-per-check from $9.95 |
| Cost per 1k words | £0.05 (Pro plan equivalent) | $0.30 |
| API available | Yes | No |
| Languages supported | 30 | 4 |
| Founded | 2024 | 2012 (AI detector 2023) |
| Country | UK | Netherlands |
| Primary audience | Educators, recruiters and content teams | Students and dissertation writers |
| Best for | Teachers, students and recruiters who want a clear confidence score and source-passage highlighting | Students already using Scribbr for proofreading or citations |
| Known weakness | Smaller brand than US incumbents | Pay-per-check pricing gets expensive fast and there is no API |
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.
Scribbr
Method: Detector white-labelled on top of Turnitin's underlying classifier per Scribbr's own published documentation.
Data handling: EU hosted. Submissions retained per Scribbr's published policy.
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 Scribbr.
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 Scribbr are vulnerable to this.
Where IsItAI wins
- Subscription pricing at £4.99/month is cheaper than Scribbr's pay-per-check model once you run more than two checks.
- API access available for teams who want to integrate detection into a marking or hiring workflow. Scribbr is web only.
- Detector built in-house. Scribbr white-labels Turnitin's classifier per its own published documentation.
Where Scribbr wins
- Bundled with Scribbr's plagiarism checker, citation generator and proofreading service for students writing dissertations.
- EU hosted, which suits non-UK European universities.
- Trusted student brand with strong recognition in the Netherlands, Germany and the wider EU.
Which one should you pick, IsItAI or Scribbr?
Pick IsItAI if you scan content regularly or want API access. Pick Scribbr if you are a student already using it for citations and proofreading and you only need an occasional one-off AI check. The two services are not as different as they look because Scribbr's detector is Turnitin underneath.
Frequently asked questions
Is IsItAI free?
5 scans/day free
Is Scribbr free?
1.2k words free
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 Scribbr?
Pick IsItAI if you scan content regularly or want API access. Pick Scribbr if you are a student already using it for citations and proofreading and you only need an occasional one-off AI check. The two services are not as different as they look because Scribbr's detector is Turnitin underneath.
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
- Scribbr AI detector
- Scribbr published comparison of AI detectors
- 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?