GPTZero (GPTZero.me) is a multi-functional AI detector that offers superior performance at a premium price. Launched in January 2023, the software provides users with a sentence-by-sentence breakdown of how a scanned text was determined to be human or AI-generated.
Additional features include detecting plagiarism and giving critical reviews to suggest changes depending on the user’s desired effect.
Pros
- Passed all 7 AI detection tests
- Passed all 8 false-positive tests
- Passed all 8 plagiarism tests
Cons
- Passed only 4 of 8 AI detection tests of humanized texts
- A low TrustPilot score suggests many dissatisfied customers
Features
- Advanced AI Scan: Scans text or documents and provides a percentage rating of how human or AI it is.
- XL Scan: Page-by-page scans of up to 50 pages at a time.
- Hallucination Detector: Verifies references and whether they support the scanned text.
- Plagiarism: Detects plagiarism and unattributed text from online sources.
- Writing Feedback: Reviews scanned text with suggestions for improvement.
- Chrome extension
- Canvas Plugin
- Zapier Plugin
- API
Pricing Plans
| Free Plan | Premium | Professional |
| Email registration required to unlock all features | $23.99/month or $155.88/year | $45.99/month or $299.88/year |
| 10,000 credits/month |
300,000 credits/month
|
500,000 credits/month |
|
Gives users access to basic AI scans, 3 free advanced scans, and 5 free AI highlights in Chrome Extension.
|
Features include advanced AI scan, download AI reports, and AI highlights in Chrome Extension.
|
All of Premium, plus 10 million words overage, enterprise-grade security LMS integration, and more. |
Credit Values
GPTZero uses a credit system, where 1 credit is exchanged per 1 word scanned. This applies across all their services, including[1]:
- Advanced AI Scan
- Hallucination Detector
- Plagiarism Detector
- Writing Feedback
The word count for each scanned document may be limited based on the user’s plan.
With the Professional Plan, users can continue scanning after exceeding their 500,000-word limit for a fractional credit fee, using their overage benefit.
Test #1: GPTZero vs LLMs
To test GPTZero’s AI-detecting abilities, we used 7 different LLMs to generate an article about President Lyndon B.Johnson. Then we used GPTZero to scan each article to see how effective it was at determining that the article was totally AI-generated.
Prompt Used
“Write a 500-word article about President Lyndon B. Johnson, providing a factual overview of his presidency while also trying to sound as human as possible and to pass AI detectors. Please remove all em dashes in your generation.”
Result:
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| LLM | Test Result | Proof |
| ChatGPT – 5.3 Thinking Model | 100% AI
✅ |
 |
| Claude – Sonnet 4.6 Extended | 100% AI
✅ |
 |
| Google Gemini – Thinking | 100% AI
✅ |
 |
| Deepseek – Deepthink | 100% AI
✅ |
 |
| Perplexity – Free Model | 100% AI
✅ |
 |
| Grok – Auto | 94% AI
✅ |
 |
| Meta | 100% AI
✅ |
 |
Test #2: GPTZero vs Humanizers
For the second test, we used the Grok-generated LBJ article because it was the only one from our first test that GPTZero graded less than 100% AI-generated.
We ran the AI-generated article through 8 different humanizers, and then scanned each of the eight new humanized articles with GPTZero to see how good it is at detecting AI in AI-generated text that’s been humanized.
Result:
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Test #3: False Positives + Plagiarism
The final test was to see whether GPTZero can correctly recognize human writing as 100% human. We did this by scanning 10 different human-written texts, including novels, articles, and interviews. Additionally, the same texts were checked for plagiarism, which should also show as 100% plagiarized because they were copied.
Result:
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| Article URL | Test Result | Proof |
| Moby Dick (Ch.1) | 100% Human, 100% Plagiarism
(passed) |
 |
| To be, or not to be | 99% Human, 98% Plagiarism
(passed) |
 |
| The Guardian (article) | 100% Human, 100% Plagiarism
(passed) |
 |
| Wikipedia (“Astrology”) | 100% Human, 100% Plagiarism
(passed) |
 |
| NPR (article) | 100% Human, 100% Plagiarism
(passed) |
 |
| Hubspot (article) | 70% Human, 100% Plagiarism
(passed) |
 |
| Interview Magazine (interview) | 100% Human, 100% Plagiarism
(passed) |
 |
| Substack (article) | 100% Human, 99% Plagiarism
(passed) |
 |
| PubMed Academic Writing | 100% Human, 100% Plagiarism
(passed) |
 |
| Stanford Article (Encyclopedia) | 100% Human, 100% Plagiarism
(passed) |
 |
Is GPTZero Accurate?
What Users Are Saying
At the time of this writing, GPTZero has a low TrustScore of only 2.4 out of 5 stars on TrustPilot.
- AI & Plagiarism Detection – Many customers complain about inaccurate AI detection, false positives, and unsatisfactory text analysis.
- Subscription and Payment – Other criticisms pertain to problems with the app’s subscription and payment system; we also encountered issues with this.
Frequently Asked Questions
Do unused credits carry over?
No, credit balances reset at the beginning of each monthly term, with any unused credits expiring.
Are sentence-by-sentence breakdowns provided?
Yes, GPTZero provides a detailed breakdown of how each sentence contributed to the AI detection score (see image).
Is document scanning included?
Yes, up to 50 pages of a pasted text, docx, pdf, or image files can be scanned at a time (see image).
Is image scanning provided?
Yes, image scans can be performed, but only for any included text.
Are reports shareable?
Yes, GPTZero scanning results are easily shared via links and PDFs (see image). When using the Chrome extension, Google Docs writing reports can also be shared.[2]
Does GPTZero provide certifications?
Yes, users who install the GPTZero Origin Chrome extension can generate a report that includes a “Certified Human” badge for Google Docs.[3]
Are AI detections used for internal training?
Yes, any documents scanned through the app dashboard are recorded to improve the software. However, documents scanned using GPTZero’s API are not recorded.[4]