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: o3 Deep Research
Claude Opus 5 (Fast) and OpenAI: o3 Deep Research are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
o3-deep-research is OpenAI's advanced model for deep research, designed to tackle complex, multi-step research tasks. Note: This model always uses the 'web_search' tool which adds additional cost.
Model details →Side-by-side comparison
| Capability | Claude Opus 5 (Fast) | OpenAI: o3 Deep Research | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 200K | 🏆 Claude Opus 5 (Fast) |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $10.00 | $10.00 | Tie |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $50.00 | $40.00 | 🏆 OpenAI: o3 Deep Research |
| 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: o3 Deep Research?
Claude Opus 5 (Fast) and OpenAI: o3 Deep Research are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
What's the price difference between Claude Opus 5 (Fast) and OpenAI: o3 Deep Research?
Input: $10.00 vs $10.00 per 1M tokens. Output: $50.00 vs $40.00 per 1M tokens.
What context windows do Claude Opus 5 (Fast) and OpenAI: o3 Deep Research support?
Claude Opus 5 (Fast) supports up to 1M tokens. OpenAI: o3 Deep Research supports up to 200K tokens.
Do both Claude Opus 5 (Fast) and OpenAI: o3 Deep Research support tool calling?
Claude Opus 5 (Fast): yes. OpenAI: o3 Deep Research: yes.
Compare Claude Opus 5 (Fast) with other models
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