GPT-5.1 vs GPT-5.5
OpenAI vs OpenAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1 has the higher intelligence index (89 vs 76.1)
- •GPT-5.1 is cheaper ($1.25 vs $5.00 per 1M input)
- •GPT-5.1 is faster
- •GPT-5.5 has a larger context window (1.1M)
| GPT-5.1 | GPT-5.5 | |
|---|---|---|
| Intelligence index | 89 | 76.1 |
| Developer | OpenAI | OpenAI |
| Type | LLM | LLM |
| Access | API only | API only |
| Context window | 400,000 tokens | 1,050,000 tokens |
| Input price | $1.25 / 1M | $5.00 / 1M |
| Output price | $10.00 / 1M | $30.00 / 1M |
| Speed | 115 tok/s | 67 tok/s |
| Released | November 12, 2025 | April 23, 2026 |
| Parameters | — | — |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
Shared benchmarks
GPT-5.1
GPT-5.5
GPQA Diamond
88.1
93.5
Humanity’s Last Exam
26.5
44.3