Overview
GPTZero is an AI content detector that identifies text generated by models like ChatGPT, GPT-4, Gemini, and Claude while evaluating writing quality. It adds hallucination detection, plagiarism and grammar checks, writing verification, and integrations for Chrome, Google Docs, and Classroom.
Our take
GPTZero is the best-known AI text detector and, to its credit, has been more careful than most about how results should be interpreted. That does not change the underlying limitation: text detection produces false positives on human writing and disproportionately flags non-native English speakers. Useful as a signal, unusable as proof.
Worth it if
Getting an indicative signal that prompts a conversation about a piece of writing.
Look elsewhere if
Any determination about a student or employee — the accuracy does not support that use.
✨ Features
AI Detection
Detects AI-generated text from ChatGPT, GPT-4, Gemini, Claude, and Llama.
Writing Verification
Offers video replay and origin verification to prove human authorship.
Hallucination & Plagiarism
Flags fake citations and checks content for plagiarism.
Integrations
Works via Chrome extension, Google Docs, Canvas, and Google Classroom.
⚖️ Pros & Cons
Pros
Cons
💰 Pricing
Essential
$15 /mo
- 150,000 words/month scanning
- AI detection
- $10/mo billed yearly
- Basic writing tools
Premium
$24 /mo
- 300,000 words/month scanning
- Advanced scan
- Writing feedback
- Plagiarism check
- Source/citation generation
Professional
$46 /mo
- 500,000 words/month scanning
- All Premium features
- Up to 10 million words overage
- Priority support
Categories
❓ Frequently Asked Questions
Can a detector result be used to fail a student?
It should not be the basis for a finding on its own, and institutions that have done so have faced well-documented unfair outcomes. False positives cluster on clear, structured prose and on writing by non-native English speakers. A score warrants a conversation, a look at drafting history, or a discussion of the work — not a penalty.
Why do detectors flag human writing?
Because they infer from statistical properties like predictability and sentence-length variation, and disciplined, conventional writing scores as predictable. That is what good technical and academic writing looks like. The same properties also characterise writing by people composing carefully in a second language, which is why the bias appears.
