Claude 2.1 vs GPT-5.1
Anthropic vs OpenAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1 has the higher intelligence index (89 vs 34.6)
- •Claude 2.1 is cheaper ($0.00 vs $1.25 per 1M input)
| Claude 2.1 | GPT-5.1 | |
|---|---|---|
| Intelligence index | 34.6 | 89 |
| Developer | Anthropic | OpenAI |
| Type | LLM | LLM |
| Access | — | API only |
| Context window | — | 400,000 tokens |
| Input price | $0.00 / 1M | $1.25 / 1M |
| Output price | $0.00 / 1M | $10.00 / 1M |
| Speed | — | 115 tok/s |
| Released | November 21, 2023 | November 12, 2025 |
| Parameters | — | — |
| Input modalities | — | Text, Image |
| Output modalities | — | Text |
Shared benchmarks
Claude 2.1
GPT-5.1
GPQA Diamond
31.9
88.1
Humanity’s Last Exam
4.2
26.5
LiveCodeBench
19.5
86.8
MMLU-Pro
49.5
87