Compare, 2 models
Side by side.
Claude Sonnet 5.5 and GPT-5.5 Pro on every board at least two of them share. Blue marks the best in each row.
Specs
List prices, context and published output speed. Blue marks the best in each row.
| Spec | Claude Sonnet 5.5Anthropic | GPT-5.5 ProOpenAI |
|---|---|---|
| Lab | Anthropic | OpenAI |
| Type | Language | Language |
| Released | Sep 28, 2026 | Apr 23, 2026 |
| Input price$ per 1M tokens | $2.00 | $30.00 |
| Output price$ per 1M tokens | $10.00 | $180.00 |
| Blended price3 input tokens per output | $4.00 | $67.50 |
| Contexttokens | 1M | 1.05M |
| Open weights | No | No |
| Output speedTok / s | 138 | n/a |
Benchmarks
Every board where at least two of these models have a published score. Each score links to its source.
| Board | Claude Sonnet 5.5Anthropic | GPT-5.5 ProOpenAI |
|---|---|---|
| Epoch Capabilities IndexOverall, higher is better | 166 | 163 |
| FrontierMath Tiers 1-3Reasoning and knowledge, higher is better | 88.8%max setting | 87.7%xhigh setting |
| GPQA DiamondReasoning and knowledge, higher is better | 95.6%max setting | 93.9%xhigh setting |
n/a means the board has not published a score for that model.