Claude Haiku 4.5 Pro vs Claude Haiku 4.5 Reasoning: which model should you choose?
We compared Claude Haiku 4.5 Pro and Claude Haiku 4.5 Reasoning on price, context window and 12 benchmarks. Claude Haiku 4.5 Reasoning has the stronger average benchmark score; Claude Haiku 4.5 Reasoning is cheaper on a blended 3:1 basis.
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
Claude Haiku 4.5 Reasoning
Claude Haiku 4.5 Reasoning is a multimodal model from Anthropic. It offers a 128,000-token context window, costs $15.11 per million input tokens and $70.05 per million output tokens, and averages 81.4 across the index's benchmark suite.
- Input
- $15.11 / 1M
- Output
- $70.05 / 1M
- Context
- 128,000
- Avg score
- 81.4
- Open weights
- No
Specification comparison
| Spec | Claude Haiku 4.5 Pro | Claude Haiku 4.5 Reasoning | Edge |
|---|---|---|---|
| Input price / 1M | $15.07 | $15.11 | A |
| Output price / 1M | $73.96 | $70.05 | B |
| Context window | 1,000,000 | 128,000 | A |
| Max output | 8,192 | 128,000 | B |
| Average score | 80.8 | 81.4 | B |
| Arena Elo | 1436.2 | 1444.2 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Haiku 4.5 Pro wins 5, Claude Haiku 4.5 Reasoning wins 7, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Haiku 4.5 Pro | Claude Haiku 4.5 Reasoning | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 81.5 | 83.4 | 1.9 | Claude Haiku 4.5 Reasoning |
| GPQA Diamond | 75.7 | 74.6 | 1.1 | Claude Haiku 4.5 Pro |
| SWE-bench Verified | 70.4 | 69.6 | 0.8 | Claude Haiku 4.5 Pro |
| HumanEval | 86.0 | 88.7 | 2.7 | Claude Haiku 4.5 Reasoning |
| MATH-500 | 83.7 | 85.8 | 2.1 | Claude Haiku 4.5 Reasoning |
| AIME 2025 | 80.1 | 79.0 | 1.1 | Claude Haiku 4.5 Pro |
| LiveCodeBench | 72.4 | 73.8 | 1.4 | Claude Haiku 4.5 Reasoning |
| IFEval | 90.1 | 89.9 | 0.2 | Claude Haiku 4.5 Pro |
| TruthfulQA | 84.1 | 82.5 | 1.6 | Claude Haiku 4.5 Pro |
| HellaSwag | 89.3 | 90.9 | 1.6 | Claude Haiku 4.5 Reasoning |
| MMMU | 75.3 | 76.7 | 1.4 | Claude Haiku 4.5 Reasoning |
| Arena Elo | 1436.2 | 1444.2 | 8.0 | Claude Haiku 4.5 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Claude Haiku 4.5 Pro costs about $29.79 per million tokens and Claude Haiku 4.5 Reasoning costs about $28.84. Claude Haiku 4.5 Reasoning is roughly 3% 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 128,000 for Claude Haiku 4.5 Reasoning. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Haiku 4.5 Pro wins 5, Claude Haiku 4.5 Reasoning wins 7, and 0 are tied. On the index average, Claude Haiku 4.5 Reasoning leads Claude Haiku 4.5 Pro by 0.6 points (81.4 versus 80.8).
The price picture favours Claude Haiku 4.5 Reasoning. 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 Haiku 4.5 Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude Haiku 4.5 Pro if
- You need the larger 1,000,000-token context window.
Choose Claude Haiku 4.5 Reasoning 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.
- The workload needs multi-step reasoning.
FAQ
Is Claude Haiku 4.5 Pro better than Claude Haiku 4.5 Reasoning?
On the index average, Claude Haiku 4.5 Reasoning leads Claude Haiku 4.5 Pro by 0.6 points (81.4 versus 80.8). The better choice depends on price, context and your task. Claude Haiku 4.5 Pro wins 5 benchmarks, Claude Haiku 4.5 Reasoning wins 7.
Which is cheaper, Claude Haiku 4.5 Pro or Claude Haiku 4.5 Reasoning?
Claude Haiku 4.5 Reasoning is cheaper on a blended 3:1 basis at about $28.84 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 Haiku 4.5 Reasoning has 128,000 tokens.
Are these models open weights?
Claude Haiku 4.5 Pro is proprietary; Claude Haiku 4.5 Reasoning is proprietary.
Which should I choose for production?
If you need a single default, start with Claude Haiku 4.5 Reasoning for quality-sensitive work, and check whether its price holds at your expected volume before committing.