Grok 4 Fast: API Pricing, Context Window & Benchmarks
Grok 4 Fast is a language model from xAI, released in August 2025, with multimodal input.
Grok 4 Fast is a high-speed variant of Grok-4, optimized for faster inference while maintaining strong reasoning capabilities. It offers improved throughput and lower latency compared to the standard Grok-4 model.
Grok 4 Fast benchmarks
Rankings
Quality Tracker
Grok 4 Fast Performance Across Datasets
Scores sourced from the model's scorecard, paper, or official blog posts
llm-stats.com - Tue Jul 21 2026Grok 4 Fast pricing
Providers
Grok 4 Fast starts at $0.200 per million input tokens and $0.500 per million output tokens via xAI.
| Provider | Input $/M | Output $/M | Context in / out | TTFT p50 / p95 s | Output avg / p5 c/s | Success 7d | Modalities in / out |
|---|---|---|---|---|---|---|---|
 xAI | $0.200 | $0.500 | 2.0M/30.0K | 0.94/1.13 | 248/23 | 100.00%(17) | / |
Cached input is the discounted price for prompt tokens served from a provider cache. TTFT is time to first token. Output is characters per second; p5 is the sustained floor exceeded by 95% of observed requests. Success is calculated from completed versus failed requests over the trailing seven days.
Grok 4 Fast context window
Input and output token limits for Grok 4 Fast, plus how it ranks on long-context understanding.
Grok 4 Fast API
Available from the model provider
Grok 4 Fast has an official provider API. It is not currently routed through the LLM Stats gateway.
Read the official API documentationGrok 4 Fast latency
Grok 4 Fast time to first token, sustained output throughput, and failed-request rate from live API traffic over the trailing 7 days.
Provider operational metrics
Time to first token, output throughput, and failed-request rate from live API traffic
Grok 4 Fast examples
Recent arena outputs from Grok 4 Fast, picked from the highest-ranked matchups.
Grok 4 Fast license
Grok 4 Fast is a proprietary model available under its provider's product and API terms.
- License
- Proprietary
- Hosted access
Proprietary license - usage restrictions apply
Grok 4 Fast resources
Official sources for Grok 4 Fast: api documentation, paper or system card.
Grok 4 Fast vs other models
The most-compared alternatives to Grok 4 Fast are Grok-3 Mini, LongCat-Flash-Thinking, Grok-4 Heavy. Open any pair side-by-side for benchmarks, pricing, context, and latency.
Models like Grok 4 Fast
Models ranked just above and below Grok 4 Fast by LLM Stats score.
FAQ
Common questions about Grok 4 Fast.