GPT Zero - Accurate AI Detector & AI Checker

Check if your text was written by ChatGPT, Gemini, or Claude. GPT Zero is the world's most trusted AI detector for writers and educators.

Trusted by students & professionals from

Harvard University
Stanford University
Cambridge University
University of Toronto
Imperial College London
How It Works

Advanced AI Detection Technology

Our AI detector looks at how text is written. It checks patterns in your sentences to figure out if a person or a machine created the content.

  • Detects ChatGPT, GPT-5.3, Gemini & Claude
  • No Sign-up Required (100% Free Forever)
  • 99.9% Accuracy Rate
AI Analysis Dashboard
Supported Models

Accurate Detection Across All Major AI Models

We can spot content from all the popular AI writing tools with great accuracy.

ChatGPT
ChatGPT
GPT-5.3
Gemini
Gemini
Pro & Ultra
Claude
Claude
Sonnet & Opus
Llama
Llama
Meta AI
Jasper
Jasper
Marketing AI
AI Detection Scans
How it Works

Understand AI Detection Scans

Our ChatGPT Detector looks at your content sentence by sentence and gives each one a score.

Learn About Detection
Why Choose Us

The Most Accurate AI Detector in the Market

Students, teachers, and professionals around the world trust us to check their content.

99.9% Detection Accuracy

We get it right almost every time. Our tool spots AI text from ChatGPT, GPT-5.3, Gemini, Claude, and other AI writers.

Lightning Fast Results

Check up to 10,000 words in just a few seconds. You get your results right away.

100% Free Forever

No hidden costs and no credit card needed. Scan as much content as you want for free.

Zero Data Retention

We don't save your text or use it for anything. What you paste stays private.

All Major AI Models

Works with ChatGPT, GPT-5.3, Gemini, Claude, Llama, Jasper, and other AI writing tools.

No Sign-up Required

Just paste your text and click scan. No account needed, no forms to fill out.

For Students & Educators

Ensure Academic Integrity with Confidence

Whether you're working on essays, research papers, or a thesis, our AI detector helps you make sure your content looks authentic before you turn it in.

  • Check essays before submitting to professors
  • Verify research papers are 100% human-written
  • Educators can verify student submissions instantly
Students using AI detector
Content creators using AI detection
For Writers & Marketers

Protect Your SEO Rankings & Brand Authenticity

Google likes content that sounds like a real person wrote it. Our AI detector helps writers, bloggers, and marketing teams check their work before publishing.

  • Verify freelancer and outsourced content quality
  • Audit blog posts before publishing for SEO compliance
  • Maintain authentic brand voice across all content
Understanding AI Detection

What is AI Content Detection?

AI content detection looks at text to figure out if a human wrote it or if it came from AI tools like ChatGPT, GPT-5.3, Gemini, or Claude.

Our detector uses smart technology to look at how sentences are put together.

Perplexity Analysis

We check how predictable the text sounds. AI tends to write in patterns, while people write with more variety.

Burstiness Detection

We look at how sentence lengths change. People naturally mix short and long sentences, while AI keeps things more even.

Our Technology

See the AI
analysis in action.

We don't just guess. Our technology looks at each sentence to check for sentence patterns and word choices that AI tends to use.

  • Detailed sentence-by-sentence highlighting
  • Distinguishes between Human, AI, and Mixed content
  • Trained on millions of academic and creative texts
Try Detection Free
AI Analysis Demo
â–¶ Watch Demo (0:58)
99%
Accuracy Rate
5M+
AI Content Detected
100K+
Happy Users
10+
AI Models Detected
Testimonials

Trusted by 100,000+ Users Worldwide

Here's what students, teachers, and professionals say about our AI detector.

"I was so worried about my essay getting flagged falsely. GPT Zero helped me identify the problematic sentences so I could rewrite them in my own voice. Lifesaver!"

S
Sarah Jenkins
University Student

"We hire dozens of freelancers and needed a way to verify originality. This tool is fast, accurate, and the free version is surprisingly generous. Highly recommend."

D
David Chen
Content Manager

"I appreciate that it doesn't just say 'AI' or 'Human' but highlights the specific parts. It helps me have constructive conversations with students about their writing."

D
Dr. Emily R.
Professor

"I use ChatGPT for outlines but write the rest myself. GPT Zero helps me ensure my final draft reads naturally and won't be penalized by Google."

M
Mark Thompson
Blogger

"The most reliable detector I've found. The interface is clean and easy to use. I love that I don't need to sign up to check a quick paragraph."

J
Jessica L.
High School Teacher

"Essential tool for my workflow. I check every piece of content before publishing. The accuracy in distinguishing between GPT-5.3 and human text is impressive."

R
Ryan P.
SEO Specialist
4.8 / 5.0
Based on 6+ reviews

How would you rate your experience?

Click a star to rate us

Featured & Trusted By Leading Institutions

Harvard University
Stanford University
Cambridge University
University of Toronto
Imperial College London
FAQ

Frequently Asked Questions

Everything you need to know about our AI content detector.

How accurate is the AI detector?

Our AI detector gets it right about 99% of the time when spotting content from ChatGPT, GPT-5.3, Gemini, Claude, and other AI tools.

Is the AI detector completely free?

Yes, completely free. No hidden charges, no credit card needed, and you can scan as often as you like.

Which AI models can you detect?

We can spot content from all the big AI writing tools including ChatGPT (GPT-5.3), Google Gemini, Anthropic Claude, Meta Llama, Jasper AI, and many others.

Is my content private and secure?

Yes, your text stays private. We don't store anything you paste. Once we check it, it's gone.

Can AI detection help with SEO?

Yes it can. Google prefers content that reads like a human wrote it. Checking your work with our AI detector before publishing can help meet Google's quality standards.

GPT Zero: Your Free AI Content Detector

GPT Zero is a free tool that analyzes text to determine whether it was written by a human or generated by artificial intelligence. With the rise of AI writing tools like ChatGPT, GPT-5.3, Claude, and Gemini, the need for reliable content verification has never been greater.

Unlike basic checkers, GPT Zero uses advanced algorithms to scan your text and provide an instant probability score. It breaks down your content sentence by sentence, highlighting specific parts that appear to be machine-generated.

The technology works by analyzing patterns in writing. AI models tend to write in predictable ways. They choose statistically common words, maintain consistent sentence lengths, and follow certain structural patterns. Human writing, on the other hand, is naturally more varied and unpredictable.