Grok-4 Fast Reasoning: Benchmarks, Pricing & Context Window
Grok-4 Fast Reasoning is a language model from xAI, released in August 2025, with multimodal input.
Pushing the Frontier of Cost-Efficient Intelligence. Grok-4 Fast Reasoning is a high-speed variant of Grok-4 optimized for faster inference while maintaining strong reasoning capabilities through thinking tokens.
Grok-4 Fast Reasoning pricing
Providers
Grok-4 Fast Reasoning starts at $0.200 per million input tokens and $0.500 per million output tokens via xAI.
| Provider | Input $/M | Output $/M | Max Input | Max Output | Latency p95 s | Throughput P95 | Quant | Input | Output |
|---|---|---|---|---|---|---|---|---|---|
 xAI | $0.200 | $0.500 | 2.0M | 30.0K | 1.58 | 34 c/s | — |
Grok-4 Fast Reasoning API
API access coming soon
Grok-4 Fast Reasoning will be available through our gateway shortly.
Grok-4 Fast Reasoning examples
Recent arena outputs from Grok-4 Fast Reasoning, picked from the highest-ranked matchups.
Grok-4 Fast Reasoning license
Grok-4 Fast Reasoning is released under the Proprietary license, which restricts commercial use.
- License
- Proprietary
- Non-commercial
Proprietary license - usage restrictions apply
FAQ
Common questions about Grok-4 Fast Reasoning.