Claude 3.7 Sonnet vs Claude Haiku 4.5 Pro: which model should you choose?
We compared Claude 3.7 Sonnet and Claude Haiku 4.5 Pro on price, context window and 12 benchmarks. Claude 3.7 Sonnet has the stronger average benchmark score; Claude 3.7 Sonnet is cheaper on a blended 3:1 basis.
Claude 3.7 Sonnet
Claude 3.7 Sonnet is a multimodal model from Anthropic. It offers a 200,000-token context window, costs $14.91 per million input tokens and $74.27 per million output tokens, and averages 81.6 across the index's benchmark suite.
- Input
- $14.91 / 1M
- Output
- $74.27 / 1M
- Context
- 200,000
- Avg score
- 81.6
- Open weights
- No
Claude Haiku 4.5 Pro
Claude Haiku 4.5 Pro is a multimodal model from Anthropic. It offers a 1,000,000-token context window, costs $15.07 per million input tokens and $73.96 per million output tokens, and averages 80.8 across the index's benchmark suite.
- Input
- $15.07 / 1M
- Output
- $73.96 / 1M
- Context
- 1,000,000
- Avg score
- 80.8
- Open weights
- No
Specification comparison
| Spec | Claude 3.7 Sonnet | Claude Haiku 4.5 Pro | Edge |
|---|---|---|---|
| Input price / 1M | $14.91 | $15.07 | A |
| Output price / 1M | $74.27 | $73.96 | B |
| Context window | 200,000 | 1,000,000 | B |
| Max output | 128,000 | 8,192 | A |
| Average score | 81.6 | 80.8 | A |
| Arena Elo | 1451.9 | 1436.2 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Claude 3.7 Sonnet wins 7, Claude Haiku 4.5 Pro wins 5, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude 3.7 Sonnet | Claude Haiku 4.5 Pro | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 83.5 | 81.5 | 2.0 | Claude 3.7 Sonnet |
| GPQA Diamond | 80.2 | 75.7 | 4.5 | Claude 3.7 Sonnet |
| SWE-bench Verified | 70.1 | 70.4 | 0.3 | Claude Haiku 4.5 Pro |
| HumanEval | 85.7 | 86.0 | 0.3 | Claude Haiku 4.5 Pro |
| MATH-500 | 88.9 | 83.7 | 5.2 | Claude 3.7 Sonnet |
| AIME 2025 | 81.2 | 80.1 | 1.1 | Claude 3.7 Sonnet |
| LiveCodeBench | 75.0 | 72.4 | 2.6 | Claude 3.7 Sonnet |
| IFEval | 88.5 | 90.1 | 1.6 | Claude Haiku 4.5 Pro |
| TruthfulQA | 81.7 | 84.1 | 2.4 | Claude Haiku 4.5 Pro |
| HellaSwag | 87.6 | 89.3 | 1.7 | Claude Haiku 4.5 Pro |
| MMMU | 75.5 | 75.3 | 0.2 | Claude 3.7 Sonnet |
| Arena Elo | 1451.9 | 1436.2 | 15.7 | Claude 3.7 Sonnet |
Price analysis
On a blended 3:1 input-to-output basis, Claude 3.7 Sonnet costs about $29.75 per million tokens and Claude Haiku 4.5 Pro costs about $29.79. Claude 3.7 Sonnet is roughly 0% cheaper than Claude Haiku 4.5 Pro. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Claude Haiku 4.5 Pro has the larger context window at 1,000,000 tokens, compared with 200,000 for Claude 3.7 Sonnet. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude 3.7 Sonnet wins 7, Claude Haiku 4.5 Pro wins 5, and 0 are tied. On the index average, Claude 3.7 Sonnet leads Claude Haiku 4.5 Pro by 0.8 points (81.6 versus 80.8).
The price picture favours Claude 3.7 Sonnet. The context picture favours Claude Haiku 4.5 Pro. Those two dimensions often matter more than a few benchmark points once a model is good enough for the task.
If you need a single default, start with Claude 3.7 Sonnet for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude 3.7 Sonnet if
- You want the higher average benchmark score in this index.
- Unit cost matters and you want the cheaper blended price.
- You need the larger 128,000-token output limit.
Choose Claude Haiku 4.5 Pro if
- You need the larger 1,000,000-token context window.
FAQ
Is Claude 3.7 Sonnet better than Claude Haiku 4.5 Pro?
On the index average, Claude 3.7 Sonnet leads Claude Haiku 4.5 Pro by 0.8 points (81.6 versus 80.8). The better choice depends on price, context and your task. Claude 3.7 Sonnet wins 7 benchmarks, Claude Haiku 4.5 Pro wins 5.
Which is cheaper, Claude 3.7 Sonnet or Claude Haiku 4.5 Pro?
Claude 3.7 Sonnet is cheaper on a blended 3:1 basis at about $29.75 per million tokens, versus $29.79 for Claude Haiku 4.5 Pro.
Which has the larger context window?
Claude Haiku 4.5 Pro has the larger context window at 1,000,000 tokens. Claude 3.7 Sonnet has 200,000 tokens.
Are these models open weights?
Claude 3.7 Sonnet is proprietary; Claude Haiku 4.5 Pro is proprietary.
Which should I choose for production?
If you need a single default, start with Claude 3.7 Sonnet for quality-sensitive work, and check whether its price holds at your expected volume before committing.