GPT-5.1 vs Phi-3.5-mini-instruct
OpenAI vs Microsoft — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1 has the higher intelligence index (89 vs 46)
- •Phi-3.5-mini-instruct is cheaper ($0.10 vs $1.25 per 1M input)
- •GPT-5.1 is faster
- •GPT-5.1 has a larger context window (400K)
| GPT-5.1 | Phi-3.5-mini-instruct | |
|---|---|---|
| Intelligence index | 89 | 46 |
| Developer | OpenAI | Microsoft |
| Type | LLM | LLM |
| Access | API only | Open weights |
| Context window | 400,000 tokens | 128,000 tokens |
| Input price | $1.25 / 1M | $0.10 / 1M |
| Output price | $10.00 / 1M | $0.10 / 1M |
| Speed | 115 tok/s | 23 tok/s |
| Released | November 12, 2025 | August 23, 2024 |
| Parameters | — | 3800000000 |
| Input modalities | Text, Image | — |
| Output modalities | Text | — |
Shared benchmarks
GPT-5.1
Phi-3.5-mini-instruct
GPQA Diamond
88.1
30.4
MMLU-Pro
87
47.4