Sonnet 5 is Anthropic's most capable Sonnet-class model, with frontier performance across coding, agents, and professional work. It supports adaptive thinking with selectable reasoning effort levels (low, medium, high, max,...
Model details →Anthropic: Claude Sonnet 5 vs OpenAI: GPT-5.6 Sol Pro
Anthropic: Claude Sonnet 5 wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5.6 Sol Pro is the same underlying model as [GPT-5.6 Sol](https://openrouter.ai/openai/gpt-5.6-sol), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://develope…
Model details →Side-by-side comparison
| Capability | Anthropic: Claude Sonnet 5 | OpenAI: GPT-5.6 Sol Pro | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 1.1M | 🏆 OpenAI: GPT-5.6 Sol Pro |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $2.00 | $5.00 | 🏆 Anthropic: Claude Sonnet 5 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $10.00 | $30.00 | 🏆 Anthropic: Claude Sonnet 5 |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | Yes | Yes | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is Anthropic: Claude Sonnet 5 better than OpenAI: GPT-5.6 Sol Pro?
Anthropic: Claude Sonnet 5 wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Anthropic: Claude Sonnet 5 and OpenAI: GPT-5.6 Sol Pro?
Input: $2.00 vs $5.00 per 1M tokens. Output: $10.00 vs $30.00 per 1M tokens.
What context windows do Anthropic: Claude Sonnet 5 and OpenAI: GPT-5.6 Sol Pro support?
Anthropic: Claude Sonnet 5 supports up to 1M tokens. OpenAI: GPT-5.6 Sol Pro supports up to 1.1M tokens.
Do both Anthropic: Claude Sonnet 5 and OpenAI: GPT-5.6 Sol Pro support tool calling?
Anthropic: Claude Sonnet 5: yes. OpenAI: GPT-5.6 Sol Pro: yes.
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