GPTZero

AI-writing detector for teachers, students, and editors who need to check text and writing process.

✓ Verified against gptzero.me · Nov 4, 2026Free tierWeb · Browser extension

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What it does

GPTZero is an AI tool for checking for plagiarism and checking grammar and spelling. It has a free plan.

GPTZero is a web and browser-extension tool that estimates whether text was written by a person or generated by an AI model. It examines writing samples, highlights passages it considers likely AI-written, and reports the result for the document as a whole. It also offers a plagiarism checker, grammar feedback, and a writing tutor for feedback. Teachers and students are a major audience, along with publishers, recruiters, and legal teams that review writing. In Google Docs, the extension can track a document's writing history; elsewhere, users can turn on Writing Replay to record sessions. Reports include typing patterns, pastes, edits, and a replay of how the text was produced. Users can ask questions about that history to see where AI assistance may have entered. Access starts with a free account. Paid team plans add shared credits, centralized billing, and seat management, and are sold by card; larger organizations can contact sales. Developers can integrate detection through an API. GPTZero states that no detector is perfect and that results should inform review rather than serve as a final judgment.

  • AI-text detection
  • Mixed-document analysis
  • Sentence-level highlighting
  • Writing Replay and typing reports
  • Plagiarism checking
  • Grammar and writing feedback
  • Chrome extension
  • Developer API

Verified facts

Each row links to the page we checked it on.
APIYes, API availablegptzero.me✓ Nov 4, 2026
Free planYes, free account availablegptzero.me✓ Nov 4, 2026
LaunchedJanuary 2023gptzero.me✓ Nov 4, 2026
PlatformsWeb and browser extensiongptzero.me✓ Nov 4, 2026
GPTZero pricing in detail →

What you can do with it

Checking for plagiarism#1 of 5Checking grammar and spelling#5 of 7

Good at

  • Free account available
  • Works in Google Docs, Classroom, Canvas, and Zapier
  • Shows writing process through replay and typing data
  • Includes plagiarism and grammar checks

Watch out for

  • No detector is fully accurate; results are not a final verdict
  • Accuracy is strongest on longer English prose
  • Full support is limited to five languages

Common questions

What is GPTZero used for?
GPTZero is used for checking for plagiarism and checking grammar and spelling. On AIToolMaps it ranks #1 of 5 for checking for plagiarism.
Is GPTZero free?
Yes. GPTZero has a free plan.
What platforms does GPTZero run on?
GPTZero runs on Web and Browser extension.
Does GPTZero have an API?
Yes. GPTZero offers an API, so developers can use it from their own code.
What are the best alternatives to GPTZero?
The closest alternatives are Originality.ai, Grammarly and QuillBot, which do most of the same jobs. Originality.ai is the closest one with a free plan.

Reviews

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Listing history

  1. Nov 4, 2026Checked against gptzero.me
  2. Sep 26, 2026Listed