Claude Sonnet 4.5 is Anthropic’s most advanced Sonnet model to date, optimized for real-world agents and coding workflows. It delivers state-of-the-art performance on coding benchmarks such as SWE-bench Verified, with improvements across sy…
Model details →Anthropic: Claude Sonnet 4.5 vs OpenAI: o1
Anthropic: Claude Sonnet 4.5 wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
The latest and strongest model family from OpenAI, o1 is designed to spend more time thinking before responding. The o1 model series is trained with large-scale reinforcement learning to reason using chain of thought. The o1 models are op…
Model details →Side-by-side comparison
| Capability | Anthropic: Claude Sonnet 4.5 | OpenAI: o1 | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 1M | 200K | 🏆 Anthropic: Claude Sonnet 4.5 |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $3.00 | $15.00 | 🏆 Anthropic: Claude Sonnet 4.5 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $15.00 | $60.00 | 🏆 Anthropic: Claude Sonnet 4.5 |
| 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 Anthropic: Claude Sonnet 4.5 better than OpenAI: o1?
Anthropic: Claude Sonnet 4.5 wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Anthropic: Claude Sonnet 4.5 and OpenAI: o1?
Input: $3.00 vs $15.00 per 1M tokens. Output: $15.00 vs $60.00 per 1M tokens.
What context windows do Anthropic: Claude Sonnet 4.5 and OpenAI: o1 support?
Anthropic: Claude Sonnet 4.5 supports up to 1M tokens. OpenAI: o1 supports up to 200K tokens.
Do both Anthropic: Claude Sonnet 4.5 and OpenAI: o1 support tool calling?
Anthropic: Claude Sonnet 4.5: yes. OpenAI: o1: yes.