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    OpenAI: GPT-5.1 Chat

    openai/gpt-5.1-chat

    Created Nov 13, 2025128,000 context
    $1.25/M input tokens$10/M output tokens$10/K web search

    GPT-5.1 Chat (AKA Instant is the fast, lightweight member of the 5.1 family, optimized for low-latency chat while retaining strong general intelligence. It uses adaptive reasoning to selectively “think” on harder queries, improving accuracy on math, coding, and multi-step tasks without slowing down typical conversations. The model is warmer and more conversational by default, with better instruction following and more stable short-form reasoning. GPT-5.1 Chat is designed for high-throughput, interactive workloads where responsiveness and consistency matter more than deep deliberation.

    Providers for GPT-5.1 Chat

    OpenRouter routes requests to the best providers that are able to handle your prompt size and parameters, with fallbacks to maximize uptime.

    Performance for GPT-5.1 Chat

    Compare different providers across OpenRouter

    Apps using GPT-5.1 Chat

    Top public apps this week using this model

    Recent activity on GPT-5.1 Chat

    Total usage per day on OpenRouter

    Uptime stats for GPT-5.1 Chat

    Uptime stats for GPT-5.1 Chat across all providers

    Sample code and API for GPT-5.1 Chat

    OpenRouter normalizes requests and responses across providers for you.

    OpenRouter provides an OpenAI-compatible completion API to 400+ models & providers that you can call directly, or using the OpenAI SDK. Additionally, some third-party SDKs are available.

    In the examples below, the OpenRouter-specific headers are optional. Setting them allows your app to appear on the OpenRouter leaderboards.

    Using third-party SDKs

    For information about using third-party SDKs and frameworks with OpenRouter, please see our frameworks documentation.

    See the Request docs for all possible fields, and Parameters for explanations of specific sampling parameters.