GPTZero
AI text detector with plagiarism checks and writing replay for educators
Own GPTZero? Claim it, free to correct the facts and get the verified badge.
Pricing
Freemium
API
Yes
Platforms
What is GPTZero?
GPTZero is an AI detection tool that estimates whether text was written by AI models such as ChatGPT, Claude and Gemini. You paste text or upload a document, and it highlights the passages it judges likely to be AI-generated. GPTZero says it can handle documents that mix human and AI writing.
Besides the detector, GPTZero offers an Advanced Scan option, a plagiarism checker, a hallucination detector and grammar and writing feedback. Writing Replay plays back how a document was written, including copy-pastes and typing patterns. It works with Google Docs, Google Classroom, Canvas, Zapier and Chrome, and developers can use the API.
GPTZero is aimed at educators, publishers, recruiters and legal teams. It fully supports English, German, Portuguese, French and Spanish. The company says it complies with SOC 2 Type II, FERPA, GDPR and CCPA.
Key features
- Detects text from ChatGPT, Claude and Gemini
- Highlights passages likely to be AI-generated
- Writing Replay shows how a document was typed
- Plagiarism checker for unattributed content
- Hallucination detector
- Grammar check and writing feedback
- Google Docs, Google Classroom, Canvas and Zapier integrations
- API with code samples in 17 languages
Use cases
Who it's for
Checking student essays
Teachers can scan submissions for AI-generated text and plagiarism, and use Writing Replay to see how an essay was written.
Editorial review
Publishers can check submitted articles for AI-written passages before publishing them.
Hiring screens
Recruiters can check cover letters and writing samples for AI-generated content.
Platform integration
Developers can add AI detection to their own products through the API.
GPTZero pricing
From the vendor's site, checked Oct 26, 2026; we re-check prices monthly. Prices change — confirm on their pricing page.
Free
Free
- Get started for free
Professional Team
per seat, billed annually or monthly
Price not shown on page
- Minimum 2 seats
- 500,000 words per member per month
- Shared team credits, unified billing, seat management
- Card payment only; contact sales for invoicing or larger teams
What the free plan gets you
- 0 / 10,000 characters per scan in the AI detector box
How GPTZero compares
- GPTZero has a free plan, like 3 of the 4 alternatives below.
- It offers an API, which only 2 of the others do.
| Tool | Starts at | Free plan | Free trial | API | Open source | |
|---|---|---|---|---|---|---|
| G | — | — | — | |||
O Originality.ai | $12.95/mo | — | — | GPTZero vs Originality.ai | ||
C Copyleaks AI Detector | $13.99/mo | — | GPTZero vs Copyleaks AI Detector | |||
| G | — | — | — | GPTZero vs Grammarly | ||
H Hemingway Editor | $8.33/mo | — | — | — | GPTZero vs Hemingway Editor |
Compare 6 capabilities
| Capability | GPTZero | Originality.ai |
|---|---|---|
| Sentence-level highlights | — | |
| Plagiarism checker | ||
| Writing replay | ||
| Bulk processing | — | |
| Shareable reports | — | |
| Docs/LMS integration |
Capabilities as stated on each vendor's own site; — means the site doesn't say. The closest alternatives in our directory by category. “Starts at” is the cheapest paid plan per month, as each vendor lists it.
GPTZero data and privacy
Trains AI on your content
Not stated
Data retention
Not stated
Where data is stored
Not stated
Security and compliance
From GPTZero's own privacy and security pages , checked Oct 28, 2026. We only show what the vendor states in writing; “not stated” means the pages don't say.
Who's behind GPTZero
- Company
- GPTZero LLC
- Based in
- New York, United States
- Founded
- 2023
- Founders
- Edward Tian, Alex Cui
“Edward Tian Co-founder and CEO Alex Cui Co-founder and CTO”
From GPTZero's own about, terms and privacy pages and Wikidata, checked Oct 28, 2026.
Pros and cons
Strengths
- Free tier available to get started
- Integrates with Google Docs, Google Classroom, Canvas and Zapier
- Fully supports five languages
- States SOC 2 Type II, FERPA, GDPR and CCPA compliance
Limitations
- Individual plan prices could not be read from the pricing page
- Team plan requires at least 2 seats and payment by card only
- No native mobile apps mentioned
GPTZero FAQ
Is GPTZero free?
Yes. You can get started for free, and paid plans are available.
Which AI models does it detect?
GPTZero says it detects text from ChatGPT, Claude, Gemini and other major models.
Is there an API?
Yes. The API lets you embed the detector in other platforms and includes code samples in 17 languages.
Where can I use it?
You can use it on the web, as a Chrome extension, and inside Google Docs, Google Classroom, Canvas and Zapier.
How do team plans work?
The Professional Team plan needs at least 2 seats and includes 500,000 words per member per month. You pay by card, or contact sales for invoicing.
User reviews
No reviews yet. Used GPTZero? Be the first.
Sign in to rate this tool and share how you use it.
GPTZero
Freemium
Tools similar to GPTZero
AI content detection, plagiarism and fact checking for publishers and educators
Detects AI-generated text and images and checks for plagiarism
AI writing assistant for grammar, tone, rewrites and AI-text detection