xAI model
Grok 4 Fast Reasoning
Model ID: grok-4-fast-reasoning
Grok 4 Fast Reasoning is a xAI model tracked in Sim. It supports a 2M token context window. Pricing starts at $0.2/1M input tokens and $0.5/1M output tokens. Key capabilities include Temperature 0-1, Tool choice. Best for cost-sensitive automations, background tasks, and high-volume workloads.
Input price
$0.2/1M
Cached input
$0.05/1M
Output price
$0.5/1M
Context window
2M
Pricing and limits
Pricing below is generated directly from the provider registry in Sim. All amounts are listed per one million tokens.
Input price
$0.2/1M
Cached input
$0.05/1M
Output price
$0.5/1M
Updated
Apr 1, 2026
Context window
2M tokens
Max output
Standard defaults
Provider
xAI
Best for
Best for cost-sensitive automations, background tasks, and high-volume workloads.
Capabilities
These capability flags are generated from the provider and model definitions tracked in Sim.
Temperature
0 to 1
Reasoning effort
Not supported
Verbosity
Not supported
Thinking levels
Not supported
Structured outputs
Not supported
Tool choice
Supported
Computer use
Not supported
Deep research
Not supported
Memory support
Supported
Max output tokens
Standard defaults
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Frequently asked questions
Grok 4 Fast Reasoning is a xAI model available in Sim. Grok 4 Fast Reasoning is a xAI model tracked in Sim. It supports a 2M token context window. Pricing starts at $0.2/1M input tokens and $0.5/1M output tokens. Key capabilities include Temperature 0-1, Tool choice.