GPT-5.1 vs Phi 4 Reasoning Plus
OpenAI vs Microsoft — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1 has the higher intelligence index (89 vs 70.4)
| GPT-5.1 | Phi 4 Reasoning Plus | |
|---|---|---|
| Intelligence index | 89 | 70.4 |
| Developer | OpenAI | Microsoft |
| Type | LLM | LLM |
| Access | API only | Open weights |
| Context window | 400,000 tokens | — |
| Input price | $1.25 / 1M | — |
| Output price | $10.00 / 1M | — |
| Speed | 115 tok/s | — |
| Released | November 12, 2025 | April 30, 2025 |
| Parameters | — | 14000000000 |
| Input modalities | Text, Image | — |
| Output modalities | Text | — |
Shared benchmarks
GPT-5.1
Phi 4 Reasoning Plus
AIME 2025
94
78
GPQA Diamond
88.1
68.9
LiveCodeBench
86.8
53.1
MMLU-Pro
87
76