Claude Opus 4.5 is Anthropic’s frontier reasoning model optimized for complex software engineering, agentic workflows, and long-horizon computer use. It offers strong multimodal capabilities, competitive performance across real-world coding…
Model details →Anthropic: Claude Opus 4.5 vs OpenAI: o3
OpenAI: o3 wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
o3 is a well-rounded and powerful model across domains. It sets a new standard for math, science, coding, and visual reasoning tasks. It also excels at technical writing and instruction-following. Use it to think through multi-step problems…
Model details →Side-by-side comparison
| Capability | Anthropic: Claude Opus 4.5 | OpenAI: o3 | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 200K | 200K | Tie |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $5.00 | $2.00 | 🏆 OpenAI: o3 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $25.00 | $8.00 | 🏆 OpenAI: o3 |
| 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 Anthropic: Claude Opus 4.5 better than OpenAI: o3?
OpenAI: o3 wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Anthropic: Claude Opus 4.5 and OpenAI: o3?
Input: $5.00 vs $2.00 per 1M tokens. Output: $25.00 vs $8.00 per 1M tokens.
What context windows do Anthropic: Claude Opus 4.5 and OpenAI: o3 support?
Anthropic: Claude Opus 4.5 supports up to 200K tokens. OpenAI: o3 supports up to 200K tokens.
Do both Anthropic: Claude Opus 4.5 and OpenAI: o3 support tool calling?
Anthropic: Claude Opus 4.5: yes. OpenAI: o3: yes.