GPTZero

AI writing detector that flags machine-generated text and checks provenance

AI Writing & CopywritingFree planOverseasβ˜…β˜…β˜…β˜…β˜† 4.0

What is GPTZero?

GPTZero is an AI detection service used mainly by teachers, editors and admissions staff. You paste or upload text and it returns a probability that the text was machine generated, with sentence-level highlighting showing which parts drove the verdict, plus a scan that looks for signs a document was pasted out of an AI chat interface. Plagiarism checks and writing-feedback tools round out the education-oriented feature set. Detection is genuinely uncertain work: false positives occur on formal or heavily edited human prose, so the right way to use a score is as one signal among several rather than as proof of anything.

Last updated: 2026-09-20. This site only provides an index; for exact features, pricing, and licensing, see the official website.

Key features

  • Machine-generated text probability from pasted or uploaded documents
  • Sentence-level highlighting showing which passages drove the score
  • Scan that looks for signs of text pasted from AI chat interfaces
  • Plagiarism checking against online sources alongside the AI score
  • Batch upload and reporting aimed at teachers marking classes
  • Writing feedback features that comment on clarity and structure

Pros & cons

Strengths

  • Sentence-level highlighting makes the verdict easier to interpret
  • Education-focused workflow with batch marking and reports
  • Combines detection with plagiarism and writing feedback in one place

Watch out for

  • False positives on formal writing, non-native English and edited drafts
  • Paraphrasing tools and newer models erode detection reliability
  • Scores should never be treated as proof of misconduct

Best for & use cases

academic integrity checks, editorial screening and ai-content research

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FAQ

Can a detector prove someone used AI?

No, and treating it that way causes harm. These tools output a probability based on statistical patterns, and confident human writing regularly scores as machine-like. Use a score to prompt a conversation, never as evidence on its own.

Why does my own writing get flagged?

Formal, repetitive or heavily edited prose shares surface features with generated text, and writers working in a second language are flagged disproportionately. Short samples are especially unreliable because there is less text to analyse.

Does it work on other languages?

English is the strongest case, with other major languages supported to varying degrees. Accuracy is generally lower outside English, so weigh the result accordingly before acting on it.