GPT-5: Key characteristics, pricing and model card

The GPT-5 model family is introduced as a competent and impressive successor to previous models, serving as a new daily-driver LLM. It is available via API in three versions—regular, mini, and nano—with four adjustable reasoning levels, and as a unified system in ChatGPT that intelligently routes queries. The pricing is aggressively competitive, with the main GPT-5 model's input cost being half that of GPT-4o. Key improvements noted in the system card include significant reductions in hallucinations and sycophancy, with a focus on enhancing performance for writing, coding, and health-related tasks. A new safety feature called "safe-completions" aims to provide moderated, helpful answers to sensitive queries rather than outright refusing them.