Grok 3 mini Fast latest vs Grok 4.1 Fast Reasoning
Grok 3 mini Fast latest vs Grok 4.1 Fast Reasoning: Grok 4.1 Fast Reasoning is cheaper by 88% on average. Grok 3 mini Fast latest from xAI (131,072-token context, reasoning, tool calls) vs. Grok 4.1 Fast Reasoning from xAI (2,000,000-token context, reasoning, tool calls). Use Agent Command Center to A/B both in shadow mode and pick the winner per workload.
Side-by-side cost
Live workload comparison
Same workload run through both models. The cheaper one is highlighted.
3,000
02,000,000
400
0200,000
5,000
01,000,000
At this workload, Grok 4.1 Fast Reasoning is 76% cheaper than Grok 3 mini Fast latest — a savings of $396/month ($4,748/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
model: grok-4-1-fast-reasoning
provider: xai
fallback:
model: grok-3-mini-fast-latest
provider: xai
shadow: { sample_rate: 0.05 } # mirror 5% of traffic to compare quality live| Grok 3 mini Fast latest | Grok 4.1 Fast Reasoning | |
|---|---|---|
| Input price | $0.600/M | $0.200/M |
| Output price | $4.00/M | $0.500/M |
| Context window | 131,072 | 2,000,000 |
| Max output | 131,072 | 2,000,000 |
| Function calling | ✓ | ✓ |
| Vision | — | ✓ |
| Audio input | — | ✓ |
| Reasoning | ✓ | ✓ |
| Prompt caching | ✓ | ✓ |
| Structured output | — | ✓ |
| Pricing verified | May 12, 2026 | May 12, 2026 |