GPTZero is a platform that detects text generated by artificial intelligence models such as GPT-3 and GPT-4. It evaluates text at sentence, paragraph, and document levels using metrics like perplexity and burstiness to determine if the content is generated by AI. The tool analyzes predictability and variability in the text to identify its origin. The platform supports operations in environments where verification of text origin is critical, such as academic settings and document authentication processes.