Detailed comparison of capabilities, features, and performance.
| Feature | GPT-5.1 codex max | Claude 4.5 Sonnet (thinking) |
|---|---|---|
| AI Lab | OpenAI | Anthropic |
| Context Size | 400,000 tokens | 1,000,000 tokens |
| Max Output Size | 128,000 tokens | 64,000 tokens |
| Frontier Model | Yes | Yes |
| Vision Support | Yes | Yes |
| Description | A version of GPT-5.1 optimized for coding tasks set in max mode. | The latest Claude 4.5 Sonnet model from Anthropic with maximum reasoning enabled, 200k reasoning tokens in 1M context. |
View detailed specifications and capabilities
View model details →View detailed specifications and capabilities
View model details →Access both GPT-5.1 codex max and Claude 4.5 Sonnet (thinking) in a single workspace without managing multiple API keys.
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