GPT 4.1 vs GPT 5.1
GPT 4.1 vs GPT 5.1: GPT 4.1 is cheaper by 38% on average. GPT 4.1 from OpenAI (1,047,576-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
01,047,576
400
0128,000
5,000
01,000,000
At this workload, GPT 5.1 is 16% cheaper than GPT 4.1 — a savings of $221/month ($2,648/year).
Crossover: GPT 5.1 is cheaper when output/input ≤ 0.38 (input-heavy workloads — RAG, retrieval). GPT 4.1 wins above (long-form generation).
Current workload ratio: 0.13 (400/3000)
Production recipe — Agent Command Center
strategy: cost-optimized
primary:
model: gpt-5-1
provider: azure-openai
fallback:
model: gpt-4-1
provider: openai
shadow: { sample_rate: 0.05 } # mirror 5% of traffic to compare quality live| GPT 4.1 | GPT 5.1 | |
|---|---|---|
| Input price | $2.00/M | $1.25/M |
| Output price | $8.00/M | $10.00/M |
| Context window | 1,047,576 | 272,000 |
| Max output | 32,768 | 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.