GPTZero

What is GPTZero?

GPTZero is an AI detection service that flags text likely written by models such as ChatGPT, Gemini and Claude. It also offers a plagiarism checker, writing feedback, a hallucination detector and Writing Replay, which shows how a document was typed.

Key capabilities of GPTZero

• AI text detection: flags text likely generated by AI models.
• Sentence-level highlighting: shows which parts of a text look AI-written.
• Writing Replay: shows how a document was typed over time.
• Plagiarism checker: compares text against existing sources.
• Hallucination detector: checks for unsupported claims in text.
• Batch scanning: scan many documents at once.

How GPTZero works

You paste text, upload a document or use an integration, and GPTZero returns a likelihood score with highlighted sentences. Writing Replay offers another signal by showing the editing history of a document.

Who uses GPTZero?

GPTZero is used by teachers, students, editors and publishers who need to check the origin of written work. The vendor claims 99.9% accuracy, which is its own figure.

GPTZero pricing

GPTZero has a free tier that scans up to 10,000 characters, and longer texts need a free account. Pricing is split into annual and monthly plans; prices are on the vendor pricing page. The Chrome extension is free.

GPTZero alternatives

Copyleaks offers AI detection and plagiarism checks for education and enterprise. Grammarly includes AI detection within a writing assistant. HyperWrite is an AI writing tool, so it generates text rather than detecting it.