What is GPTZero?
GPTZero launched in January 2023 and has since grown into one of the most widely adopted AI content detectors, serving more than 10 million users and hundreds of institutions. The tool addresses a straightforward problem: as large language models produce increasingly fluent prose, educators, editors, and organizations need a way to tell machine writing from human writing. Rather than returning a single opaque verdict, GPTZero analyzes text for measurable patterns—predictability, sentence variation, and tonal repetition—and shows which parts of a document look machine-generated.
GPTZero is a dedicated AI content checker that scans any document and identifies text likely produced by a large language model (LLM). It works at a granular level, highlighting the specific sentences or passages that display machine-generated patterns instead of just grading the whole file. Its proprietary model evaluates perplexity (how predictable the word choices are), burstiness (how much sentence structure varies), and whether the tone is overly generic or repetitive.
That combination supports everything from quick paragraph checks to full essay and manuscript reviews.
