Claude Opus 5 is Anthropic’s flagship model for demanding reasoning, coding, and long-horizon agentic work. It is particularly strong at end-to-end software tasks, code review and bug finding, visual analysis...
Model details →Claude Opus 5 vs OpenAI: GPT-5.6 Luna Pro
OpenAI: GPT-5.6 Luna Pro wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5.6 Luna Pro is the same underlying model as [GPT-5.6 Luna](https://openrouter.ai/openai/gpt-5.6-luna), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://devel…
Model details →Side-by-side comparison
| Capability | Claude Opus 5 | OpenAI: GPT-5.6 Luna 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 Luna Pro |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $5.00 | $0.10 | 🏆 OpenAI: GPT-5.6 Luna Pro |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $25.00 | $0.60 | 🏆 OpenAI: GPT-5.6 Luna Pro |
| 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 Claude Opus 5 better than OpenAI: GPT-5.6 Luna Pro?
OpenAI: GPT-5.6 Luna Pro wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Claude Opus 5 and OpenAI: GPT-5.6 Luna Pro?
Input: $5.00 vs $0.10 per 1M tokens. Output: $25.00 vs $0.60 per 1M tokens.
What context windows do Claude Opus 5 and OpenAI: GPT-5.6 Luna Pro support?
Claude Opus 5 supports up to 1M tokens. OpenAI: GPT-5.6 Luna Pro supports up to 1.1M tokens.
Do both Claude Opus 5 and OpenAI: GPT-5.6 Luna Pro support tool calling?
Claude Opus 5: yes. OpenAI: GPT-5.6 Luna Pro: yes.
Compare Claude Opus 5 with other models
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