Grok 4 vs Grok 4.1 Fast
Grok 4 vs Grok 4.1 Fast: Grok 4.1 Fast is cheaper by 97% on average. Grok 4 from xAI (256,000-token context, tool calls) vs. Grok 4.1 Fast 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 is 95% cheaper than Grok 4 — a savings of $2,161/month ($25,933/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
model: grok-4-1-fast
provider: xai
fallback:
model: grok-4
provider: xai
shadow: { sample_rate: 0.05 } # mirror 5% of traffic to compare quality live| Grok 4 | Grok 4.1 Fast | |
|---|---|---|
| Input price | $3.00/M | $0.200/M |
| Output price | $15.00/M | $0.500/M |
| Context window | 256,000 | 2,000,000 |
| Max output | 256,000 | 2,000,000 |
| Function calling | ✓ | ✓ |
| Vision | — | ✓ |
| Audio input | — | ✓ |
| Reasoning | — | ✓ |
| Prompt caching | ✓ | ✓ |
| Structured output | — | ✓ |
| Pricing verified | May 12, 2026 | May 12, 2026 |
Benchmark comparison
Side-by-side public benchmark scores. Greener bar = winner.