OpenAI: GPT-5.1 Chat

GPT-5.1 Chat is a paid text-and-vision model from OpenAI that also accepts file uploads alongside images and text. It supports tool use, offers a 128,000-token context window, and can return up to 32,000 completion tokens per request. It does not include a built-in reasoning mode, and structured output support is unconfirmed from available data. At $1.25 per million input tokens and $10.00 per million output tokens, the output cost is notably steep compared to many mid-tier competitors, which makes it most practical for workloads where output volume is modest relative to input. There is currently no independent benchmark coverage to reference, so performance claims rest entirely on vendor materials. Buyers who need multimodal file handling and tool integration within a large context window may find it worth evaluating, but the unproven benchmark standing warrants running your own evals before committing at this price.