ToolFlock

GPTZero

GPTZero is an AI detector that estimates whether text was written by a person, by AI or by both, and highlights the sentences behind its score. It also checks for plagiarism and invented citations and plugs into Google Docs and learning platforms.

#12 in Writing & Translation ToolsAI DetectorsPlagiarism CheckersFree plan

Who it's for

Best for

  • Teachers who want a first signal before a conversation
  • Editors screening submissions for AI text
  • Students who want to verify draft originality before submission

Not for

  • Anyone treating one score as proof
  • Teams that require consistent scores across different detectors

Pricing

Free plan$0
Premium$23.99/mo
Professional$45.99/mo

Features

  • AI detection

    Estimates whether text is human, AI-generated or mixed, and gives a probability for each.

  • Sentence highlights

    Highlights the sentences that drive the score, showing which parts look AI-written.

  • Plagiarism and citation checks

    Checks text against web sources and flags citations that look invented or cannot be found.

  • Writing replay

    Google Docs extension replays how a document was written to show the drafting history.

  • Classroom integrations

    Connects with learning platforms such as Canvas and Google Classroom.

What users say

Pros

  • Picks up AI-written passages that other free detectors miss, even after light editing.
  • Splits a text into human, mixed and AI shares instead of giving one bare score.
  • Its source finder and citation check flag made-up references and unsupported claims.

Cons

  • Marks entirely hand-written text as fully AI-generated.
  • Scores the same college essay far apart from QuillBot, ZeroGPT and Copyleaks.
  • Calls polished, idiomatic human writing 100% AI while Turnitin rates the same paper 0%.

A selection of the review sources we used:

Summarized from public user reviews and community discussions. View details

Global Traffic Rank

Top 50k

Alternatives

GPTZeroPlagiarismCheck.orgScribbrOriginality.ai
Rank#12 in category#17 in category#18 in category#28 in category
Free planYesYesYesYes
ProCatches edited AI text and shows a human, mixed, AI splitEarly red flags, clear reports, per-article checks, AI detectionHandy citation tool, explained proofreading, solid checksCatches AI text and shows which parts look generated
Better forAgencies and web publishers screening freelance posts with shared team credits and readability checks.
Weaker atConnecting directly with school learning platforms like Canvas and Google Classroom.