AI Detector

Our free AI Detector gives you a fast, clear answer. Paste any text and get instant results showing whether it's AI-generated or human-written — along with deep analysis you can trust.

Text to Analyze

Enter the text you want to check for AI content

0 words

Detection Results

AI content analysis and probability scores

Enter text and click "Detect AI Content" to see results

What Is an AI Detector?

An AI Detector is a tool that checks if a piece of text was written by a human or generated by an AI model like ChatGPT, GPT-4, or Gemini. It does this by looking at patterns, sentence style, word use, and structure that AI tends to repeat.

Our tool uses advanced AI detection models trained on thousands of human and machine samples — so it knows what to look for. It shows a score for both AI probability and human probability, plus a full breakdown of sentence-level results.

How Our AI Content Detector Works

Most AI-generated content follows set patterns — even when it looks "natural." Our detector picks up on those patterns using a few key checks:

Perplexity: Measures how predictable each sentence is. AI often writes in very clear, structured ways with low perplexity.
Burstiness / Length Variation: Human writing tends to have more natural variation — some short, some long sentences. AI stays more even.
Semantic Flow: AI can repeat ideas in different words. Our tool catches these rewrites and patterns.
Probability Scoring: Shows how likely your content was made by a language model.

Every piece of text is analyzed deeply. You'll see if your content is safe, or if it might get flagged by AI detection tools like GPTZero, Originality.ai, Turnitin AI, and others.

Why Use an AI Detector?

AI writing tools are everywhere. While they help speed up writing, they also leave behind a trace — and that can cause issues.

For Students

Many schools now check for AI-written work. Our detector helps you make sure your essays sound human — before you submit.

For Writers and Editors

Freelancers, marketers, and content teams can check work before publishing or handing it off to clients.

For Teachers

Check student work to spot AI use, reuse, or pattern-based writing.

For SEO & Web Teams

Avoid being flagged by Google's AI spam filters by testing and adjusting your AI-assisted content.

Features You Can Rely On

Real-time AI detection

Highlights of AI-sounding phrases

Human vs. AI probability scores

No sign-up or login needed

Free to use — forever

Built to catch ChatGPT, Claude, Gemini, Jasper, and more

Sample Detection: How We Flag AI

Take the example shown in the image:

AI Probability: 98%

Human Probability: 2%

🔎 The tool highlights areas with predictable structure, repeated phrasing, and low complexity. This is a common sign of ChatGPT-style writing. Even when the content sounds formal or academic, AI often misses human nuance — and our system catches that.

Who Should Use This Tool?

Our AI content detector is trusted by:

Students who want to avoid false AI flags

Writers checking AI-assisted drafts

Bloggers and marketers optimizing content

Teachers reviewing assignments for originality

Businesses making sure their team isn't overly reliant on AI

Editors reviewing guest posts or outsourced content

Why Trust UndetectAI's AI Detector?

We don't just flag content — we give you clear scores, context, and proof. Many tools give vague guesses. We show sentence-level detection and explain why a line was flagged.

Built for Accuracy

Trained on the latest models (ChatGPT, GPT-4, Claude, Gemini) with updated patterns.

Regularly Updated

AI models change fast — and so do we. Our system evolves to stay one step ahead.

Free Forever

No cost, no credit card. Just open the tool and paste your content.

Try the AI Detector Now — Free & Fast

Don't guess if content is human or AI-written. Know it. Use UndetectAI's free AI Detector to check text, get AI/human scores, and make smart edits before you publish, submit, or share.

Start now — No login needed. Works instantly.