How much does GPT-5.1 cost?

GPT-5.1 is listed at $1.25/1M input tokens, $0.125/1M cached input tokens, and $10/1M output tokens.

What is the context window for GPT-5.1?

GPT-5.1 supports a context window of 400k tokens in Sim. In an agent, this determines how much conversation history, tool outputs, and retrieved documents the model can hold in a single call.

What is GPT-5.1 best used for?

Best for reasoning-heavy tasks that need more deliberate model control. When used in a Sim workflow, it can be selected in any Agent block from the model picker.

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OpenAI model

GPT-5.1

Name: GPT-5.1
Brand: OpenAI
SKU: gpt-5.1

GPT-5.1 is a OpenAI model tracked in Sim. It supports a 400k token context window. Pricing starts at $1.25/1M input tokens and $10/1M output tokens. Key capabilities include Tool choice, Structured outputs, Reasoning none, low, medium, high. Best for reasoning-heavy tasks that need more deliberate model control.

Build with this model All OpenAI models

Input price$1.25/1M

Cached input$0.125/1M

Output price$10/1M

Context window400k

Max output128k tokens

ProviderOpenAI

UpdatedApr 1, 2026

Best forBest for reasoning-heavy tasks that need more deliberate model control.

TemperatureNot configurable

Reasoning effortnone, low, medium, high

Verbositylow, medium, high

Thinking levelsNot supported

Structured outputsSupported

Tool choiceSupported

Computer useNot supported

Deep researchNot supported

Memory supportSupported

Max output tokens128k

Frequently asked questions

GPT-5.1 is a OpenAI model available in Sim. GPT-5.1 is a OpenAI model tracked in Sim. It supports a 400k token context window. Pricing starts at $1.25/1M input tokens and $10/1M output tokens. Key capabilities include Tool choice, Structured outputs, Reasoning none, low, medium, high.