AI Detector by QuillBot

QuillBot’s AI content detector is a tool that analyzes text and estimates whether it was likely generated by AI. It examines writing patterns commonly associated with AI-generated text such as predictability, repetition, and structural consistency and produces a confidence score indicating the likelihood that the content was created by an AI model.

There’s two main reasons that QuillBot’s AI Detector is different from other AI detectors. First, we distinguish how AI was used to create your content. Our analysis will tell you if each section of writing was:
1) AI-generated
2) Human-written & AI-refined
3) Human-written

This way, you don’t just know if AI may have been used to generate the content. You can also understand how assistive tools may have been used in the writing process.

Second, we offer feedback on every section of your writing, so you always know exactly which sentences appear to contain AI-generated content. This makes your editing process much easier, as you can quickly identify and adjust any problematic sections of your text.

QuillBot’s AI Detector analyzes patterns in writing to estimate the probability that text was generated by AI. Instead of making a simple yes-or-no judgment, the tool provides a confidence score that reflects how closely the text matches patterns commonly found in AI-generated writing. These patterns may include predictability, repetition, and structural consistency often associated with large language models.

The detector is designed to evaluate text produced by modern AI systems such as GPT-5, GPT-4, Claude, Gemini, and similar models. As with all AI checker tools, accuracy can vary depending on factors like text length, topic, and how the content was written or edited. In general, longer passages provide more reliable signals, which helps improve overall AI checker accuracy.

QuillBot’s AI checker is designed to analyze text generated by modern large language models (LLMs). This includes content produced by systems such as GPT-5, GPT-4, Claude, Gemini, Llama, and other advanced AI writing models. Because AI models evolve quickly, QuillBot’s detection system is continuously updated to recognize patterns from newer models and versions. This helps the tool stay effective as AI writing technology advances.

AI detection analyzes writing patterns to estimate whether text was likely generated by AI.

Plagiarism detection, on the other hand, checks whether text matches existing content published online or in academic databases. It identifies copied or closely similar passages and links them to their original sources.In short, AI detection asks “Was this likely written by AI?”, while plagiarism detection asks “Was this copied from somewhere else?” A piece of writing can be original but AI-generated, or plagiarized without involving AI at all.

Yes, QuillBot’s AI Detector for teachers can report the likelihood that text in essays and other class assignments is AI-generated.

Teachers use all sorts of AI detectors to support academic integrity and evaluate student work. QuillBot’s AI Detector is a great resource for educators who want to make sure their students are producing original work and for students who want to make sure they have not relied too heavily on AI.

Yes. QuillBot’s AI checker can analyze text that may contain a mix of human and AI-generated writing. Instead of evaluating a document as a single block, the tool examines patterns across the text and identifies sections that may match signals commonly associated with AI-generated content.

No. QuillBot’s AI Detector does not verify whether a piece of writing is definitively human or original. Instead, it analyzes patterns in the text and estimates the probability that the content was generated by AI based on signals commonly associated with AI-written language.

QuillBot’s AI Detector is designed to detect AI-generated text it doesn’t analyze images, videos, or other rich media. To check whether an image was AI-generated, you can use QuillBot's

AI Image Detector

QuillBot’s AI Detector is useful for a wide range of professionals who need to review text for potential AI generation. Educators can evaluate student assignments, while journalists and editors can review drafts and submissions to maintain editorial standards. SEO teams and digital marketers use an AI checker to review web content before publishing and maintain quality across large content pipelines.The tool is also helpful for researchers and technical writers reviewing reports or documentation, as well as enterprise teams managing internal or client-facing content.

The AI writing detector only identifies text generated by artificial intelligence. QuillBot has a host of other tools, including a

Grammar Checker

No. The AI Detector content checker will inform you of any AI-generated content, while our

Plagiarism Checker

Yes. QuillBot’s AI Detector supports 20+ languages, allowing users to analyze AI-generated text across a wide range of global content. This makes it useful for international teams, educators, and publishers working with multilingual writing. Some of the commonly supported languages include English, Spanish, French, German, and Portuguese, along with many others.

Yes. While QuillBot’s AI Detector focuses on identifying patterns associated with AI-generated text, it also connects directly with QuillBot’s writing tools to help refine flagged content. If sections of text are identified as likely AI-generated, users can quickly improve or adjust the writing using integrated tools within the same workflow. For example, you can use QuillBot’s Humanizer to make AI-assisted text sound more natural and aligned with your voice or use the Paraphraser to rewrite sentences for greater clarity, variation, and originality.

Our AI detector flags text that may be AI-generated. Use your best judgment when reviewing results. Never rely on AI detection alone to make decisions that could impact someone's career or academic standing.

Yes. QuillBot plans to integrate its AI Detector directly into QuillBot Chat and browser extensions, allowing users to check text for AI-generated patterns without leaving their writing environment.