GPT-5.1 Instant is the fastest model in the GPT-5.1 family, optimized for low-latency responses across general-purpose tasks, delivering GPT-5.1 generation quality at speeds suited for real-time applications.
import { streamText } from 'ai'
const result = streamText({ model: 'openai/gpt-5.1-instant', prompt: 'Why is the sky blue?'})GPT-5.1 Instant was released on November 12, 2025 as part of the GPT-5.1 model generation on AI Gateway. It's optimized for speed across general-purpose tasks, targeting applications where response latency is the binding constraint.
The model brings GPT-5.1 generation improvements to a speed-first profile. It handles chat, content generation, summarization, analysis, and other general-purpose tasks at latencies designed for real-time interaction. The context window of 128K tokens supports substantial input lengths even in speed-optimized mode.
If you're building real-time products, GPT-5.1 Instant eliminates the tradeoff between model generation quality and response speed. It shows what the GPT-5.1 architecture can deliver when optimized primarily for throughput and latency rather than maximum reasoning depth.