GPT-4 Turbo vs GPT 5.1
GPT-4 Turbo vs GPT 5.1: GPT 5.1 is cheaper by 88% on average. GPT-4 Turbo from OpenAI (128,000-token context, tool calls) vs. GPT 5.1 from Azure OpenAI (272,000-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
0272,000
400
0128,000
5,000
01,000,000
At this workload, GPT 5.1 is 82% cheaper than GPT-4 Turbo — a savings of $5,212/month ($62,549/year).
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
model: gpt-5-1
provider: azure-openai
fallback:
model: gpt-4-turbo
provider: openai
shadow: { sample_rate: 0.05 } # mirror 5% of traffic to compare quality live| GPT-4 Turbo | GPT 5.1 | |
|---|---|---|
| Input price | $10.00/M | $1.25/M |
| Output price | $30.00/M | $10.00/M |
| Context window | 128,000 | 272,000 |
| Max output | 4,096 | 128,000 |
| 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.