GPTZero is an AI content detector that scans text from models like ChatGPT, Claude, and Gemini, serving educators, writers, and teams verifying originality.
About
GPTZero is an AI detection platform built to identify text generated by AI models such as ChatGPT, Claude, Gemini, GPT-5, and Llama. It addresses a growing problem for teachers, editors, and publishers: determining whether a piece of writing was produced by a person or a machine. Users paste text into the detector and receive an overall AI score along with sentence-by-sentence results.
Beyond basic detection, GPTZero offers tools for verifying authentic writing, including a writing replay feature that records the document creation process, showing typing patterns and copy-paste actions. The platform also includes a plagiarism checker, writing feedback, a hallucination detector, and a Chrome extension that runs detection inside tools like Gmail and Google Docs. GPTZero reports more than 20 million users, including over 2 million educators, and it lists the American Federation of Teachers as an official partner. A developer API is available for integrating detection into other platforms.
Key Features
Pricing & Fees
- Pricing: GPTZero offers a free tier and paid plans with monthly and annual billing; a Professional Team plan includes 500,000 words per member per month with shared credits and unified billing. Exact individual plan prices are not publicly listed on the pages we reviewed; check the official site for current plans.
- Free access: A free AI detector is available on the site, and the Google Docs add-on is free to install.
- Scale: GPTZero reports over 20 million users, more than 2 million educators, and use in over 100 countries.
- Education focus: Integrates with learning management systems such as Canvas and Google Classroom, and offers classroom-oriented workflows for teachers.
- Developer API: Ready-to-use code is available in 17 languages, including Node.js, Python, C#, Java, and PHP.
Who It's For
GPTZero is aimed primarily at educators and students who need to check essays and assignments for AI-generated content, and at institutions that want classroom-level integration through Canvas or Google Classroom. It also serves writers, editors, and freelancers who want to prove their work is human-written using writing replay reports, plus recruiters and publishers screening submitted text. Developers can embed detection into their own products through the API, and teams can manage shared usage under a single billing plan.
FAQ
What is GPTZero?GPTZero is an AI detector that identifies text generated by models such as ChatGPT, Claude, Gemini, and Llama, providing an overall AI score and sentence-by-sentence results.
Is there a free version of GPTZero?Yes, GPTZero offers a free AI detector on its website and a free Google Docs add-on, with paid plans and a team plan offering larger word allowances and shared credits.
Which tools does GPTZero integrate with?It integrates with Google Docs, Google Classroom, Canvas, Gmail and other sites through a Chrome extension, and offers Zapier support plus an API with code samples in 17 programming languages.
Does GPTZero detect more than ChatGPT output?No single-model limitation applies; GPTZero classifies text from multiple major AI models, including Claude, Gemini, Llama, and GPT-5, and also checks for plagiarism.
Can GPTZero prove that writing is human?It offers writing replay and authorship reports that record the writing process, including typing and paste events, which users can share as evidence of authentic writing.
Related Tutorials
View all →
Related Tools
View all →
Winston AI Winston AI is an AI content detector and plagiarism checker that identifies text generated by ChatGPT, Claude, Gemini and other models, with image detection and OCR for educators, publishers and writers. 
Resemble AI Resemble AI is a multimodal deepfake detection platform that identifies AI-generated audio, video, and images in real time, with watermarking and identity verification for enterprises. 
Clever AI Detector Free online AI text checker — probability scores with sentence-level signals, up to 10,000 words per check, unlimited runs. 
ZeroGPT ZeroGPT is a free AI content detector that checks text for ChatGPT, GPT-4, Gemini, Claude and other LLM output, alongside writing tools like a humanizer, paraphraser and plagiarism checker. 
PlagiarismCheck.org PlagiarismCheck.org is a web-based plagiarism checker and AI-content detector that helps teachers, students, writers, and institutions assess text originality and verify authorship.