Free ChatGPT Detector — Detect ChatGPT Text
Instantly identify text written by ChatGPT, GPT-4, and GPT-4o with 99.2% accuracy on unmodified output. Built for educators, content managers, and hiring teams.
Paste text & click Analyze, or try a sample
How ChatGPT Text Is Detected#
ChatGPT produces text with distinctively low perplexity — it consistently chooses the most statistically probable next word, creating unnaturally smooth, uniform prose. Our ChatGPT detector measures this alongside sentence-length variance, formal transition frequency, and vocabulary repetition patterns to identify ChatGPT-generated content with 99.2% accuracy. Learn more about how AI detection technology works.
ChatGPT vs Human Writing: Key Differences#
Human writing exhibits natural burstiness — alternating between longer and shorter sentences, occasionally starting sentences with conjunctions, and making unexpected word choices. ChatGPT output tends toward consistent sentence length, overuse of transitional phrases like "Furthermore" and "In conclusion", and a formal register even on casual prompts. Our detector identifies these characteristic ChatGPT patterns. See our accuracy analysis for detailed breakdown by model.
What the ChatGPT Detector Analyzes#
- Perplexity score (low = likely AI-generated by ChatGPT)
- Sentence length burstiness and uniformity
- Transition word overuse typical of GPT models
- Vocabulary diversity and repetition patterns
- Semantic coherence and structural patterns
Detect All GPT Versions#
Our ChatGPT detector works on text from GPT-3.5, GPT-4, GPT-4 Turbo, and GPT-4o. Each version has slightly different characteristics, and our detection engine is trained to recognize patterns from all GPT model generations. Need to check for Claude-generated text instead? We cover that too. You can also run your text through our plagiarism checker to ensure content isn't copied from existing sources.