AI Detector by Grammarly

Grammarly’s AI detector tool displays a percentage that indicates how much of the text provided appears AI-generated, as assessed by our detection model. Our machine-learning model is trained on hundreds of thousands of human and AI-generated texts. Grammarly breaks your text into smaller sections, checking each section against the model for language patterns typically indicative of AI text. Grammarly then returns a % score, indicating how much of the provided text appears AI-generated. It assesses whether text resembles AI-generated writing; like other AI text checkers, it cannot provide a definitive conclusion.


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While AI detectors can help assess whether text appears to be AI-generated, currently there is no AI detector that can conclusively or definitively determine whether AI was used to produce text. That’s because the accuracy of these tools can vary based on the algorithms used and the specific characteristics of the text being analyzed. AI detection tools should be just one part of a holistic approach to evaluating writing originality.

If you're seeking a more detailed and reliable way to prove the originality of your work or show your writing process more clearly, try Grammarly Authorship. Authorship automatically categorizes your text as you write based on where it came from. Unlike traditional AI detectors, which analyze and estimate the likelihood that text is AI-generated or plagiarized post-submission, Authorship works by using Grammarly’s on-browser presence and access to your clipboard (with your consent) to label text that is typed, copied from an AI-generated source, copied from a website, rephrased with Grammarly’s AI, or edited with grammar and spelling corrections. With Authorship, you also receive a shareable report, ideal for sharing with professors, supervisors, or editors. Plus, Authorship’s replay feature allows you to review your document's creation from the first word to the final punctuation mark, providing an additional layer of validation for your writing process.

Yes, AI content detectors can be biased. They may misinterpret writing styles and flag content as less authentic—especially with writers whose primary language is not English. This happens because AI often learns from a majority-language pattern, which might not account for the diverse ways people write.


That’s why Grammarly is committed to building models using quality datasets that undergo comprehensive evaluations for bias and fairness. We design and develop products with our team of analytical linguists who apply their research and expertise to minimize bias and apply user feedback. Learn more about our principles of responsible AI development.

No AI detector is 100% accurate. This means you should never rely on the results of an AI detector alone to determine whether AI was used to generate content. AI detectors can indicate characteristics found in human-written text as well as characteristics commonly found in AI-generated writing, such as language patterns that seem robotic or generic. But, they cannot definitively conclude whether or not AI was used. These tools should be one part of a holistic approach to evaluating writing originality.

Yes, Grammarly’s AI detector and other ChatGPT checkers can identify text produced by AI models like ChatGPT, Gemini, Claude, Microsoft Copilot, and more. To learn more about all things AI, visit the Grammarly blog.

Your writing might be flagged for AI if it exhibits patterns, structures, or characteristics typical of text that has been created with generative AI. Learn more about why your writing may have been flagged on the Grammarly blog.

Grammarly's AI content detection feature is currently available for Grammarly Premium, Grammarly Business, and Grammarly for Education subscribers. Use it in Grammarly for Windows and Mac and the Grammarly Editor. It will soon become available for more of our product offerings, enabling you to check your text across even more applications and websites. The AI detector tool on this page is compatible with any browser. For guidance on getting started with Grammarly's AI detection feature, visit our support page.

What is and is not cheating can be subjective—what one professor considers acceptable might be off-limits to another. It also varies based on the assignment and how you intend to use AI. When writing in an academic setting, always comply with your institution’s and educator’s AI usage policies, typically found in course syllabi or academic-integrity guidelines. 

If you use AI, we recommend you disclose it with a citation. Grammarly can instantly generate citations for AI usage when you use AI tools.