Fast-mode variant of [Opus 4.8](/anthropic/claude-opus-4.8) - identical capabilities with higher output speed at 2x pricing relative to regular Opus 4.8. Learn more in Anthropic's docs: https://platform.claude.com/docs/en/build-with-claude…
Model details →Anthropic: Claude Opus 4.8 (Fast) vs DeepSeek Reasoner (legacy id)
Anthropic: Claude Opus 4.8 (Fast) wins on 5 of 6 axes — pricing and capability skew in its favour for most workloads.
Legacy compatibility id mapping to DeepSeek V4 Flash thinking mode (per DeepSeek pricing notes).
Model details →Side-by-side comparison
| Capability | Anthropic: Claude Opus 4.8 (Fast) | DeepSeek Reasoner (legacy id) | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 1M | Tie |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $10.00 | Custom | 🏆 Anthropic: Claude Opus 4.8 (Fast) |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $50.00 | Custom | 🏆 Anthropic: Claude Opus 4.8 (Fast) |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | — | 🏆 Anthropic: Claude Opus 4.8 (Fast) |
| Vision input Accepts image inputs alongside text. | Yes | — | 🏆 Anthropic: Claude Opus 4.8 (Fast) |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | — | 🏆 Anthropic: Claude Opus 4.8 (Fast) |
Frequently asked questions
Is Anthropic: Claude Opus 4.8 (Fast) better than DeepSeek Reasoner (legacy id)?
Anthropic: Claude Opus 4.8 (Fast) wins on 5 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Anthropic: Claude Opus 4.8 (Fast) and DeepSeek Reasoner (legacy id)?
Input: $10.00 vs Custom per 1M tokens. Output: $50.00 vs Custom per 1M tokens.
What context windows do Anthropic: Claude Opus 4.8 (Fast) and DeepSeek Reasoner (legacy id) support?
Anthropic: Claude Opus 4.8 (Fast) supports up to 1M tokens. DeepSeek Reasoner (legacy id) supports up to 1M tokens.
Do both Anthropic: Claude Opus 4.8 (Fast) and DeepSeek Reasoner (legacy id) support tool calling?
Anthropic: Claude Opus 4.8 (Fast): yes. DeepSeek Reasoner (legacy id): not advertised.
Compare Anthropic: Claude Opus 4.8 (Fast) with other models
vs Anthropic Claude Haiku Latestvs Anthropic Claude Sonnet Latestvs Anthropic: Claude Fable Latestvs Anthropic: Claude Opus Latest