GPTZero
Education-focused detector with per-sentence highlighting, document reports and a writing-replay feature for Google Docs that shows how a draft was typed.
What it is
GPTZero grew out of the first wave of ChatGPT detection in early 2023 and now sells mostly to schools. Besides the per-sentence score, its Google Docs writing replay records how a document was typed, which is a different kind of evidence: process rather than style. That matters because process evidence is what survives a paraphrase. The free checker is enough for a quick look; reports and volume are paid.
When to use this entry
Use this entry for a widely used free checker and for process-based evidence in education.
Questions
How accurate is GPTZero?
GPTZero publishes its own figures and third-party tests vary widely. No detector should decide an outcome alone.
What is writing replay?
A feature that records the typing history of a Google Doc so a reader can watch how the text was produced.