General Questions
What is AI Detector?
AI Detector is a free tool that analyzes text to determine whether it was likely written by a human or generated by an AI model like ChatGPT, Claude, or Gemini. Unlike most detectors, it provides word-level highlighting and rewrite suggestions — not just a percentage score.
Is it free?
Yes, 100% free. No sign-up, no email required, no usage limits, no “premium tier” hiding the good features.
Does it work on any AI model?
It detects patterns common across all major large language models (LLMs), including:
- OpenAI: GPT-3.5, GPT-4, GPT-4o, GPT-4o mini
- Anthropic: Claude 3, Claude 3.5
- Google: Gemini, Gemini Pro
- Meta: LLaMA 3
- Mistral: Mixtral, Mistral Large
- Others: Cohere, Yi, Qwen, DeepSeek
Accuracy & Reliability
How accurate is AI detection?
On unedited AI-generated text, accuracy is typically 85-95%. On edited or mixed content, accuracy drops significantly. No detector achieves 100%. Read our full accuracy analysis.
What is a false positive?
A false positive occurs when human-written text is incorrectly flagged as AI-generated. This happens more often with:
- Formal or academic writing
- Technical documentation
- Non-native English speakers
- Formulaic content (legal, medical)
Learn more: Why AI Detectors Give False Positives
What is a false negative?
A false negative occurs when AI-generated text is incorrectly identified as human-written. This is more common with:
- Heavily edited AI text
- AI text run through paraphrasing tools
- Short text samples (under 100 words)
Can students use this to check their own work?
Yes. If you’re worried your writing style might trigger a false positive, run it through AI Detector to see which sentences are flagged and adjust them before submitting.
Should AI detector scores be used as evidence?
No. AI detector scores are statistical estimates, not proof. They should be used as one signal among many — never as the sole basis for academic or professional decisions. Why AI detectors get it wrong.
Features
What is word-level highlighting?
Instead of just saying “82% AI-generated,” our word-level heatmap colors individual words based on how AI-like they appear. Hover over any word to see its score. This lets you see exactly what triggered the result.
What are rewrite suggestions?
For sentences flagged as AI-generated, we provide rewrite suggestions — alternative phrasings that sound more natural and human. This is especially useful for writers who use AI as a starting point and want to personalize the output.
What signals does the detector analyze?
Five core signals:
- AI phrase frequency — Known AI-overused phrases (“furthermore,” “it is worth noting”)
- Sentence uniformity — How evenly-paced the sentences are
- Lexical diversity — Vocabulary range (type-token ratio)
- Punctuation patterns — Comma-to-dash ratios
- Word-level statistical scoring — Per-word AI probability
Privacy & Security
Does AI Detector store my text?
No. All analysis runs entirely in your browser using JavaScript. No text is sent to any server, stored in any database, or used for training.
Is my data private?
Yes. Since analysis happens client-side, we never see your text. There’s nothing to leak, sell, or breach.
Do you use cookies?
Only for theme preference (light/dark mode). No tracking cookies, no analytics cookies, no third-party scripts.
Comparison
How does AI Detector compare to GPTZero?
GPTZero is one of the most accurate paid detectors. AI Detector offers similar detection with additional features (word heatmap, rewrite suggestions) for free. See our full comparison.
How does it compare to Originality.ai?
Originality.ai is designed for content agencies and charges per scan. AI Detector is free and unlimited. For agency-scale use, Originality.ai offers batch processing; for individual checks, AI Detector is faster and costs nothing.
Which is the best free AI detector?
We compared 5 free options in our guide: 5 Best Free AI Detectors (No Sign-Up Required).