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
OpenAI: GPT-5 wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5 is OpenAI’s most advanced model, offering major improvements in reasoning, code quality, and user experience. It is optimized for complex tasks that require step-by-step reasoning, instruction following, and accuracy...
Model details →Side-by-side comparison
| Capability | Claude Opus 5 (Fast) | OpenAI: GPT-5 | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 400K | 🏆 Claude Opus 5 (Fast) |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $10.00 | $1.25 | 🏆 OpenAI: GPT-5 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $50.00 | $10.00 | 🏆 OpenAI: GPT-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 Claude Opus 5 (Fast) better than OpenAI: GPT-5?
OpenAI: GPT-5 wins on 2 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?
Input: $10.00 vs $1.25 per 1M tokens. Output: $50.00 vs $10.00 per 1M tokens.
What context windows do Claude Opus 5 (Fast) and OpenAI: GPT-5 support?
Claude Opus 5 (Fast) supports up to 1M tokens. OpenAI: GPT-5 supports up to 400K tokens.
Do both Claude Opus 5 (Fast) and OpenAI: GPT-5 support tool calling?
Claude Opus 5 (Fast): yes. OpenAI: GPT-5: yes.
Compare Claude Opus 5 (Fast) with other models
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