ChatPDF uses a retrieval-augmented generation (RAG) architecture to build a semantic map of uploaded documents, enabling fast and accurate question answering with inline source citations. The platform performs dynamic model routing between GPT-4o and GPT-4o-mini to balance speed, quality, and cost efficiency. It supports multiple file formats including PDF, DOCX, PPTX, MD, and TXT, and allows multi-document conversations via folder-based organization. All data is protected with SSL encryption in transit and at rest, backed by SOC2 Type II certified infrastructure.