OpenAI: GPT-5.1 Chatopenai
Bottom Line
OpenAI: GPT-5.1 Chat: $1.25/1M input, $10.00/1M output, 128K context. 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...
API Pricing (per 1M tokens)
| Input | $1.25 |
| Output | $10.00 |
| Cache Read | — |
| Cache Write | — |
| Blended (3:1) | $3.44 |
Specs & Performance
| Context Length | 128K |
| Max Output | 32K |
| Intelligence | — |
| Coding | — |
| Math | — |
| Speed | — |
| TTFT | — |
| CPS Grade | — |
| Input / Output Modalities | file, image, text → text |
More from openai
Looking for cheaper alternatives?
Find the cheapest model by task, or compare two models head-to-head.
FAQ
How much does the OpenAI: GPT-5.1 Chat API cost?
OpenAI: GPT-5.1 Chat costs $1.25/1M input tokens and $10.00/1M output tokens. Blended cost at a 3:1 ratio is about $3.44/1M tokens.
What is the context window of OpenAI: GPT-5.1 Chat?
OpenAI: GPT-5.1 Chat supports a 128K token context window with up to 32K output tokens.
Is OpenAI: GPT-5.1 Chat worth it?
OpenAI: GPT-5.1 Chat has a CPS grade of — (score —), intelligence index —, coding index —. Use the compare page to benchmark against rivals.