How do I interpret a GPTZero result?

A GPTZero result has two parts: a class and a confidence.

The class is one of:

• AI. A highly confident result reads: “We are highly confident this text was AI generated.”

• Mixed. A highly confident result reads: “We are highly confident this text is a mix of AI and human.”

• Human. A highly confident result reads: “We are highly confident this text is entirely human.”

Confidence is highly confident, moderately confident, or uncertain.

How does AI detection work?

AI tools like ChatGPT produce text with subtle but detectable patterns in word choice, sentence structure, and style — think of it like a writing fingerprint. Our model has learned to recognize these patterns by studying millions of AI-generated and human-written documents, and uses them to estimate the probability that a given text was written by AI. Our model is over 99% accurate across multiple subject areas and languages.

The AI detection score is not the percentage of AI in the document.

A score of “75% AI” means our model is 75% confident the entire document was written by AI. It does not mean that 75% of the sentences are AI-written. The score reflects how closely the document’s writing patterns match AI-generated text in our database.

Mixed and Human use the same rule. The percentage is the model’s confidence in that classification of the entire text. It is not the share of the document that is mixed or human.

What if the AI score is in the 40%–70% range?

Scores in this range mean the text has some characteristics of AI writing, but not enough for a confident classification. If your document is in this range, scan more documents by the same author, or use GPTZero’s AI authorship tools.

When should I believe that someone is using AI?

If we are highly confident about the AI classification, and the result is above 90–95% AI, the text was very likely AI generated. GPTZero never recommends using a detection score as the sole basis for academic consequences. A high AI score is the starting point for a conversation with a student, not the final verdict. We recommend educators use our behind-the-scenes Writing Report for a holistic assessment. See our FAQ for more information.