Fast-mode variant of [Opus 5](/anthropic/claude-opus-5) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 5. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude/fast-…
Model details →Claude Opus 5 (Fast) vs OpenAI: GPT-5.6 Sol
OpenAI: GPT-5.6 Sol wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series. It is suited for complex reasoning, coding, and agentic workflows, and is particularly strong at command-line and multi-step coding tasks...
Model details →Side-by-side comparison
| Capability | Claude Opus 5 (Fast) | OpenAI: GPT-5.6 Sol | 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 |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $10.00 | $5.00 | 🏆 OpenAI: GPT-5.6 Sol |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $50.00 | $30.00 | 🏆 OpenAI: GPT-5.6 Sol |
| 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 (Fast) better than OpenAI: GPT-5.6 Sol?
OpenAI: GPT-5.6 Sol 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 (Fast) and OpenAI: GPT-5.6 Sol?
Input: $10.00 vs $5.00 per 1M tokens. Output: $50.00 vs $30.00 per 1M tokens.
What context windows do Claude Opus 5 (Fast) and OpenAI: GPT-5.6 Sol support?
Claude Opus 5 (Fast) supports up to 1M tokens. OpenAI: GPT-5.6 Sol supports up to 1.1M tokens.
Do both Claude Opus 5 (Fast) and OpenAI: GPT-5.6 Sol support tool calling?
Claude Opus 5 (Fast): yes. OpenAI: GPT-5.6 Sol: yes.
Compare Claude Opus 5 (Fast) with other models
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