Claude Haiku 4.5 Reasoning vs GPT-4.1: which model should you choose?
We compared Claude Haiku 4.5 Reasoning and GPT-4.1 on price, context window and 12 benchmarks. GPT-4.1 has the stronger average benchmark score; GPT-4.1 is cheaper on a blended 3:1 basis.
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
GPT-4.1
GPT-4.1 is a multimodal model from OpenAI. It offers a 1,000,000-token context window, costs $15.71 per million input tokens and $64.52 per million output tokens, and averages 82.4 across the index's benchmark suite.
- Input
- $15.71 / 1M
- Output
- $64.52 / 1M
- Context
- 1,000,000
- Avg score
- 82.4
- Open weights
- No
Specification comparison
| Spec | Claude Haiku 4.5 Reasoning | GPT-4.1 | Edge |
|---|---|---|---|
| Input price / 1M | $15.11 | $15.71 | A |
| Output price / 1M | $70.05 | $64.52 | B |
| Context window | 128,000 | 1,000,000 | B |
| Max output | 128,000 | 16,384 | A |
| Average score | 81.4 | 82.4 | B |
| Arena Elo | 1444.2 | 1432.4 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Haiku 4.5 Reasoning wins 5, GPT-4.1 wins 7, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Haiku 4.5 Reasoning | GPT-4.1 | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 83.4 | 86.2 | 2.8 | GPT-4.1 |
| GPQA Diamond | 74.6 | 76.1 | 1.5 | GPT-4.1 |
| SWE-bench Verified | 69.6 | 72.2 | 2.6 | GPT-4.1 |
| HumanEval | 88.7 | 88.3 | 0.4 | Claude Haiku 4.5 Reasoning |
| MATH-500 | 85.8 | 86.8 | 1.0 | GPT-4.1 |
| AIME 2025 | 79.0 | 79.9 | 0.9 | GPT-4.1 |
| LiveCodeBench | 73.8 | 77.8 | 4.0 | GPT-4.1 |
| IFEval | 89.9 | 90.4 | 0.5 | GPT-4.1 |
| TruthfulQA | 82.5 | 81.8 | 0.7 | Claude Haiku 4.5 Reasoning |
| HellaSwag | 90.9 | 90.3 | 0.6 | Claude Haiku 4.5 Reasoning |
| MMMU | 76.7 | 76.3 | 0.4 | Claude Haiku 4.5 Reasoning |
| Arena Elo | 1444.2 | 1432.4 | 11.8 | Claude Haiku 4.5 Reasoning |
Price analysis
On a blended 3:1 input-to-output basis, Claude Haiku 4.5 Reasoning costs about $28.84 per million tokens and GPT-4.1 costs about $27.91. GPT-4.1 is roughly 3% cheaper than Claude Haiku 4.5 Reasoning. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
GPT-4.1 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 Reasoning wins 5, GPT-4.1 wins 7, and 0 are tied. On the index average, GPT-4.1 leads Claude Haiku 4.5 Reasoning by 1.0 points (82.4 versus 81.4).
The price picture favours GPT-4.1. The context picture favours GPT-4.1. 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 GPT-4.1 for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude Haiku 4.5 Reasoning if
- You need the larger 128,000-token output limit.
Choose GPT-4.1 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 1,000,000-token context window.
FAQ
Is Claude Haiku 4.5 Reasoning better than GPT-4.1?
On the index average, GPT-4.1 leads Claude Haiku 4.5 Reasoning by 1.0 points (82.4 versus 81.4). The better choice depends on price, context and your task. Claude Haiku 4.5 Reasoning wins 5 benchmarks, GPT-4.1 wins 7.
Which is cheaper, Claude Haiku 4.5 Reasoning or GPT-4.1?
GPT-4.1 is cheaper on a blended 3:1 basis at about $27.91 per million tokens, versus $28.84 for Claude Haiku 4.5 Reasoning.
Which has the larger context window?
GPT-4.1 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 Reasoning is proprietary; GPT-4.1 is proprietary.
Which should I choose for production?
If you need a single default, start with GPT-4.1 for quality-sensitive work, and check whether its price holds at your expected volume before committing.