Arena Elo 1150Human-preference rating · LMArena (shown where the model is ranked)
Capabilities
7-day heat trend
−17.1%Pricing breakdown
Typical 3:1 output-to-input mix, per 1M tokens
Estimated monthly cost by workload
Market position
- Cheaper than 28% of tracked models
- Faster than 60% of tracked models
- Efficiency rank: #43 of 1105
Best suited for
Complex reasoning, analysis, planning and multi-step problem solving where answer quality matters more than raw cost.
About grok-4-fast-reasoning
Grok 4 Fast is a cost-efficient xAI reasoning model with a very large context window.
grok-4-fast-reasoning is a Reasoning model from xAI (US). HotON.ai tracks it at $0.20 per 1M input tokens and $0.50 per 1M output tokens, with a 2000K-token context window, ~153 tokens/sec throughput and 98.0% availability. Its composite efficiency score is 96/100 at an estimated $0.001 per successful task.
Compare grok-4-fast-reasoning
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Frequently asked questions
How much does grok-4-fast-reasoning cost per 1M tokens?+
grok-4-fast-reasoning is tracked at $0.20 per 1M input tokens and $0.50 per 1M output tokens. A typical 3:1 output-to-input workload blends to roughly $0.42 per 1M tokens. Figures are illustrative demo data.
What is grok-4-fast-reasoning best for?+
Complex reasoning, analysis, planning and multi-step problem solving where answer quality matters more than raw cost.
How fast is grok-4-fast-reasoning?+
grok-4-fast-reasoning delivers about 153 tokens/sec with 98.0% tracked availability, suitable for latency-sensitive, real-time applications.
Is grok-4-fast-reasoning cheaper than other AI models?+
Within the HotON.ai tracked set, grok-4-fast-reasoning is cheaper than 28% of models on input price and ranks #43 of 1105 by overall efficiency.
Related models
Pricing is real (via the TestKey catalog, updated daily). Quality (Arena Elo) is real where the model is ranked on LMArena. Speed, availability and efficiency are modeled estimates.