Quillbot's free AI Detector checks text from ChatGPT, GPT-5, Claude and others. Get an AI score, sentence-level highlights, and refined AI detection insights.
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Analyze text with the AI Detector for a detailed report of the possible use of AI writing tools

AI Detector by Quillbot

Paste your text below to check whether it was written by AI. Our AI detector is trained to detect content generated by GPT-5, Gemini, Claude, Llama, and more.
AI Detector by Quillbot

Paste your text below to check whether it was written by AI. Our AI detector is trained to detect content generated by GPT-5, Gemini, Claude, Llama, and more.

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What is an AI detector?





An AI detector (also called an AI checker or AI content detector) analyzes text to evaluate how likely it was generated by AI. It searches for patterns common to AI-generated text and determines how likely it is the writer used a platform like GPT-4, GPT-5, ChatGPT or Claude. AI content detection is used by educators, editors, SEO professionals, and businesses to make sure content is original.

How accurate is Quillbot’s AI detector?

Our free AI detector is continuously updated as language models evolve, keeping it up-to-date with the latest AI tools and models.

Trained on the latest LLMs

Stay ahead of the curve with software updated regularly to scan for new patterns from GPT-5, Claude, ChatGPT, Gemini, and other LLMs as they evolve.

Accuracy and reliability

Detect AI text reliably with a 99% detection rate, according to independent evaluations from

RAID

. Get AI likelihood estimates you can trust and avoid false positives.

Multilingual support

Work with AI-generated text across multiple languages.

Instant detection

Get results in seconds, allowing you to review text without slowing down your workflow.

Privacy-first design

Keep your text secure, so your sensitive or unpublished content stays protected.

Insights and explanations

Understand why text scores the way it does.

Downloadable reports

Get results you can share with other educators, editors, or teams.

Transparent results

Get clear scores and explanations to help users understand why text may be flagged as AI-generated.

Scores are signals, not verdicts. Never make an academic or employment decision on a detector score alone, and if you used AI in your work, disclose it rather than revising to change a score. See our

Academic Integrity page

.

How to use Quillbot’s free AI checker

Input text

Paste or type what you want to be scanned for AI detection. To improve accuracy, make sure it's at least 80 words long.

Run scan and review

Select "Detect AI" to receive a score from 0–100% on how likely the scanned text was AI-generated, then read the explainer card to understand why it was flagged.

Review and act

Read the explainer cards to understand your results. Revise passages that read stiff or generic. Premium users can download and share the full report.

What makes Quillbot different from other AI detection tools?

Paraphrasing and grammar checking tools help millions of writers refine text and express their ideas. But most AI checkers can’t differentiate between text that’s been entirely generated with AI tools and text that’s been refined using AI assistance. Quillbot offers a more reliable AI Detector.

How do AI detectors differentiate between human and AI-generated text?

AI detectors evaluate common indicators of AI-generated writing such as how predictable the text is, variation in sentence structure, and repetitiveness. The tool assigns a percentage score from 0 to 100% indicating the likelihood that the text was generated by AI. A minimum of 80 words is required to scan. As with any AI checker; the longer the text the better the results.

When the result is unclear, our model tends to classify texts as human written, which reduces false positives. For the most accurate results, analyze your entire text at once, and make sure it meets the length requirement. Always interpret results in light of your own knowledge.

When the AI Detector tool identifies sections of text as likely AI-written, it provides explainers with insights into why that text was flagged. As with any AI detector, this score is not a guarantee, but it is a useful signal when authorship matters.

AI Detector: Explore free vs. Premium features

Try writing in different tones of voice.

Free
Word limit

Up to 1,200 words per scan

Daily usage

Up to 6 scans per day

Limited explainer cards

1 free explainer card explaining necessary changes

Access to Quillbot Tools

Includes Grammar Checker, Humanizer, and Plagiarism Checker

premium
Premium
Word limit

No word limit for detection scans

Daily usage

Unlimited scans

Detailed explainers across the full text

Unlimited explainer cards explaining necessary changes

Access to Quillbot Tools

Full access to all Quillbot tools for a complete writing workflow

Certify your
human-written content

If you’re a site owner or blogger, get a Quillbot certificate for your published page and add a verification badge to your site. Build trust with readers, reduce AI skepticism, and keep proof of authenticity one click away.

Get certified

Go beyond text: 
Detect AI in images

AI isn’t limited to text, images can be also created with

AI Image generators

. Ensure images and visuals used in your work are not generated by AI with Quillbot's AI image detector.

What’s the difference between an AI detector and a plagiarism checker?

An AI detector checks if content was likely generated by AI. A plagiarism detector checks if content was copied from somewhere else. A piece of writing can be original but AI-generated, or copied from another source without involving AI. Using both tools together helps evaluate authenticity and originality.

Supporting writers at top institutions
AI Detector for Institutes
Try AI Detection Free

Who can use Quillbot’s
AI detector?

Educators

Review assignments and essays for likely AI use as one input among several in a conversation with the student.

SEO and digital professionals

Check articles and web content for AI-generated patterns before publishing to maintain credibility

Marketers

Review campaign copy, blogs, and product content for AI patterns to maintain audience trust

Publishers and content teams

Screen submissions or drafts for potential AI-generated text

Do it all with Quillbot

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AI detector-related guides and resources

Why people love our
AI detector

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The AI tool i use the most

I spend every day drafting, creating, and editing content. This tool saves me a ton of time. I mostly use its Paraphraser, grammar and AI Detector. It's definitely worth the Premium version.

Whitney W.

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Great assistant

This app has made it much easier for me to check my students' writing assignments for any AI use. Other AI checker tools seemed inconsistent and had trouble flagging writing as AI, but this one has always done great job at finding and flagging AI assisted writing.

Patricia D. B.

Quote

It gives me accurate results that no…

It gives me accurate results that no other AI checker gives. I myself spent time on writing my coursework just for an AI checker like Zerogpt to tell me its at least 60 percent AI? Quillbot checker gives me 0 percent AI on my work which wrote myself and that kinda gives me a sense of relieve. Thank you.

Oriya

Coming soon

Real-time AI Content detection where you already work

Detect AI-generated content while chatting or editing inside Quillbot’s AI Chat and browser extensions. No switching tools. No delays.

AI detector FAQs

Quillbot’s AI content detector is a tool used for analyzing text to check whether or not it was generated using AI writing software. It looks for writing patterns that are associated with AI, like repetitive or predictable phrases, and then gives a confidence score between 0 and 100% that states the likelihood of the text being AI or human written.

There are two major factors that set apart Quillbot’s AI detector from other similar tools.

First, it distinguishes how the text was created using AI (whether it was entirely AI-written, entirely human-written, or human-written with some AI refinement). This way, you get a clearer understanding of how your text was created, rather than just told whether or not it was made with AI.

Second, feedback is provided for each section of your writing, so you will always have a clear understanding of which sentences and phrases are flagged for AI writing. This makes the editing process much simpler, as you can save time by focusing primarily on rewriting the flagged sections of your text.

QuillBot is independently evaluated on

RAID

, a third-party benchmark covering ChatGPT, GPT-4, GPT-5, Claude, Gemini, Mistral, Llama, and more.

QuillBot's free AI writing detector is built on advanced LLM-based linguistic pattern analysis, continuously trained on large datasets to stay current with the latest AI writing systems.

Our models are designed to deliver high accuracy across all content types, lengths, and writing styles, while minimizing false positives to ensure human-written content is not wrongly flagged.

Key things that make our detection reliable:
  • Up-to-date models: Keeps pace with the latest AI writing tools like ChatGPT as they evolve
  • Broad model coverage: Detects content from all major AI systems including ChatGPT, Gemini, Claude, and Copilot
  • Low false positive commitment: Built to avoid flagging human writing
  • Multilingual support: Detects AI text across multiple languages
What affects accuracy:
  • Longer texts (300+ words) produce more reliable scores than short inputs
  • Heavily paraphrased or lightly AI-edited content is harder to detect for any AI checker
  • Formulaic human writing (academic definitions, legal copy, structured templates) can score higher than expected for any AI writing detector
Note that no AI Detector can provide 100% accuracy. As language models like ChatGPT continue to evolve, detection tools must continuously adapt to keep up, which is why our models are regularly retrained and refined. Results are probability estimates, not verdicts. Use them as one input in a wider review.

Quillbot’s free AI detector is designed to analyze text generated by modern large language models (LLMs). This includes AI models like GPT-5, GPT-4, Claude, Gemini, ChatGPT, Llama, and other similar models. Since

AI models are always changing and evolving, Quillbot’s AI detector is regularly updated to account for newer AI models and versions. This allows the tool to stay more accurate and effective at spotting AI writing as technology advances.

All AI checkers present the risk of false positives, or incorrect identification of AI use. Heavily paraphrased writing and highly formulaic content, such as legal jargon or academic writing, is more likely to present a false positive.

Quillbot’s AI checker accounts for AI-refined text specifically, reducing false positives for text that was written by a human but edited with AI.

Educators should use AI checkers as one input in a wider conversation with students. Our free 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’s AI detector can be helpful for teachers by determining the likelihood of whether their students' writing was created using the help of AI writing tools.

Teachers use a range of AI detectors. Quillbot’s AI Detector gives educators sentence-level insight into likely AI use. Students can use it to make sure their own original text doesn't appear to be AI-generated. Always disclose AI use under your institution’s policies.

Yes. Quillbot’s AI checker can also help to determine if a piece of writing features a mix of both human and AI writing. Rather than just simply evaluating an entire text as a single block of writing, the tool examines writing patterns line-by-line, identifying and flagging specific sections as being AI-generated.

No. Quillbot’s AI detector can not verify whether a piece of writing was created by a human or original. The tool simply analyzes a piece of text and searches for common AI writing patterns and estimates the probability of it being created with the use of an AI writing tool.

Quillbot’s AI detector is specifically designed to detect AI-generated text. It doesn’t analyze images, videos, or other types of media. If you would like to check whether an image was AI-generated, you can use Quillbot's

AI Image Detector

.

Quillbot’s AI detector can benefit professionals across many different industries. Educators can use it for evaluating student assignments, while journalists and editors can screen drafts or submissions from other writers. SEO teams and digital marketers can use AI detectors to review web content prior to publishing and maintaining quality across their content pipelines. Researchers and technical writers can use the tool for reviewing reports or documentation, and enterprise teams can utilize it for managing internal or client-facing content.

No, the AI detector is solely used to detect AI writing. Quillbot has many other tools, including a

Grammar checker

, Plagiarism checker,

Paraphraser

and a humanize AI tool that you can use separately, in addition to the AI detector, if you want to improve your writing further beyond AI detection.

No. Quillbot’s AI detector can help you to scan and find AI-written content within a piece of writing, but it does not scan text for plagiarism. Use our

Plagiarism Checker

if you want to scan a piece of text for plagiarism.

Yes. Quillbot’s AI detector supports 20+ languages. This makes it useful for international teams, educators, and publishers working with multilingual writing. Supported languages include English, Spanish, French, Portuguese, and many others.

Yes. The AI Detector focuses on analysis, but it can also help with better writing. If flagged passages read stiff or generic, tools like the Grammar Checker and Paraphraser can help you revise for clarity and flow. One thing the workflow is not for: making undisclosed AI use harder to spot. If AI contributed to your work, follow your institution’s or employer’s rules on acknowledging it. See our

Academic Integrity page

to learn more.

Our AI detector simply identifies and flags text that might be AI-generated, but it is not perfect. Use your best judgment when reviewing results. Never rely on an AI detector alone when making 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. This will give users the ability to check text for AI-generated patterns without ever having to leave their primary writing space.

That’s not what it’s for. The AI Detector helps users ensure original content and helps protect human-written work from being falsely flagged. If AI contributed to your work, disclose it under your institution’s or employer’s guidelines. See our

Academic Integrity page

for guidance.