Claude Haiku 4.5 Pro vs Gemini 3 Flash: which model should you choose?
We compared Claude Haiku 4.5 Pro and Gemini 3 Flash on price, context window and 12 benchmarks. Gemini 3 Flash has the stronger average benchmark score; Gemini 3 Flash 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
Gemini 3 Flash
Gemini 3 Flash is a multimodal model from Google DeepMind. It offers a 128,000-token context window, costs $15.67 per million input tokens and $70.15 per million output tokens, and averages 83.6 across the index's benchmark suite.
- Input
- $15.67 / 1M
- Output
- $70.15 / 1M
- Context
- 128,000
- Avg score
- 83.6
- Open weights
- No
Specification comparison
| Spec | Claude Haiku 4.5 Pro | Gemini 3 Flash | Edge |
|---|---|---|---|
| Input price / 1M | $15.07 | $15.67 | A |
| Output price / 1M | $73.96 | $70.15 | B |
| Context window | 1,000,000 | 128,000 | A |
| Max output | 8,192 | 65,536 | B |
| Average score | 80.8 | 83.6 | B |
| Arena Elo | 1436.2 | 1450.7 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Haiku 4.5 Pro wins 0, Gemini 3 Flash wins 12, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Haiku 4.5 Pro | Gemini 3 Flash | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 81.5 | 83.7 | 2.2 | Gemini 3 Flash |
| GPQA Diamond | 75.7 | 80.3 | 4.6 | Gemini 3 Flash |
| SWE-bench Verified | 70.4 | 72.5 | 2.1 | Gemini 3 Flash |
| HumanEval | 86.0 | 86.2 | 0.2 | Gemini 3 Flash |
| MATH-500 | 83.7 | 89.0 | 5.3 | Gemini 3 Flash |
| AIME 2025 | 80.1 | 84.5 | 4.4 | Gemini 3 Flash |
| LiveCodeBench | 72.4 | 79.3 | 6.9 | Gemini 3 Flash |
| IFEval | 90.1 | 91.0 | 0.9 | Gemini 3 Flash |
| TruthfulQA | 84.1 | 84.8 | 0.7 | Gemini 3 Flash |
| HellaSwag | 89.3 | 89.8 | 0.5 | Gemini 3 Flash |
| MMMU | 75.3 | 78.2 | 2.9 | Gemini 3 Flash |
| Arena Elo | 1436.2 | 1450.7 | 14.5 | Gemini 3 Flash |
Price analysis
On a blended 3:1 input-to-output basis, Claude Haiku 4.5 Pro costs about $29.79 per million tokens and Gemini 3 Flash costs about $29.29. Gemini 3 Flash is roughly 2% 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 Gemini 3 Flash. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Haiku 4.5 Pro wins 0, Gemini 3 Flash wins 12, and 0 are tied. On the index average, Gemini 3 Flash leads Claude Haiku 4.5 Pro by 2.8 points (83.6 versus 80.8).
The price picture favours Gemini 3 Flash. 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 Gemini 3 Flash 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 Gemini 3 Flash 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 65,536-token output limit.
- The workload needs multi-step reasoning.
FAQ
Is Claude Haiku 4.5 Pro better than Gemini 3 Flash?
On the index average, Gemini 3 Flash leads Claude Haiku 4.5 Pro by 2.8 points (83.6 versus 80.8). The better choice depends on price, context and your task. Claude Haiku 4.5 Pro wins 0 benchmarks, Gemini 3 Flash wins 12.
Which is cheaper, Claude Haiku 4.5 Pro or Gemini 3 Flash?
Gemini 3 Flash is cheaper on a blended 3:1 basis at about $29.29 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. Gemini 3 Flash has 128,000 tokens.
Are these models open weights?
Claude Haiku 4.5 Pro is proprietary; Gemini 3 Flash is proprietary.
Which should I choose for production?
If you need a single default, start with Gemini 3 Flash for quality-sensitive work, and check whether its price holds at your expected volume before committing.