Claude 3.7 Sonnet Max vs Gemini 3 Flash Reasoning: which model should you choose?
We compared Claude 3.7 Sonnet Max and Gemini 3 Flash Reasoning on price, context window and 12 benchmarks. Claude 3.7 Sonnet Max and Gemini 3 Flash Reasoning are effectively tied on the index average; Gemini 3 Flash Reasoning is cheaper on a blended 3:1 basis.
Claude 3.7 Sonnet Max
Claude 3.7 Sonnet Max is a frontier model from Anthropic. It offers a 128,000-token context window, costs $16.88 per million input tokens and $83.20 per million output tokens, and averages 83.7 across the index's benchmark suite.
- Input
- $16.88 / 1M
- Output
- $83.20 / 1M
- Context
- 128,000
- Avg score
- 83.7
- Open weights
- No
Gemini 3 Flash Reasoning
Gemini 3 Flash Reasoning is a frontier model from Google DeepMind. It offers a 128,000-token context window, costs $17.05 per million input tokens and $66.77 per million output tokens, and averages 83.7 across the index's benchmark suite.
- Input
- $17.05 / 1M
- Output
- $66.77 / 1M
- Context
- 128,000
- Avg score
- 83.7
- Open weights
- No
Specification comparison
| Spec | Claude 3.7 Sonnet Max | Gemini 3 Flash Reasoning | Edge |
|---|---|---|---|
| Input price / 1M | $16.88 | $17.05 | A |
| Output price / 1M | $83.20 | $66.77 | B |
| Context window | 128,000 | 128,000 | Tie |
| Max output | 32,768 | 32,768 | Tie |
| Average score | 83.7 | 83.7 | Tie |
| Arena Elo | 1461.6 | 1446.9 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Claude 3.7 Sonnet Max wins 6, Gemini 3 Flash Reasoning wins 6, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude 3.7 Sonnet Max | Gemini 3 Flash Reasoning | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 86.0 | 87.2 | 1.2 | Gemini 3 Flash Reasoning |
| GPQA Diamond | 76.8 | 81.8 | 5.0 | Gemini 3 Flash Reasoning |
| SWE-bench Verified | 76.1 | 72.5 | 3.6 | Claude 3.7 Sonnet Max |
| HumanEval | 90.9 | 86.9 | 4.0 | Claude 3.7 Sonnet Max |
| MATH-500 | 87.2 | 86.2 | 1.0 | Claude 3.7 Sonnet Max |
| AIME 2025 | 80.7 | 79.4 | 1.3 | Claude 3.7 Sonnet Max |
| LiveCodeBench | 78.1 | 77.7 | 0.4 | Claude 3.7 Sonnet Max |
| IFEval | 90.0 | 90.2 | 0.2 | Gemini 3 Flash Reasoning |
| TruthfulQA | 84.7 | 86.6 | 1.9 | Gemini 3 Flash Reasoning |
| HellaSwag | 91.2 | 92.2 | 1.0 | Gemini 3 Flash Reasoning |
| MMMU | 78.8 | 79.8 | 1.0 | Gemini 3 Flash Reasoning |
| Arena Elo | 1461.6 | 1446.9 | 14.7 | Claude 3.7 Sonnet Max |
Price analysis
On a blended 3:1 input-to-output basis, Claude 3.7 Sonnet Max costs about $33.46 per million tokens and Gemini 3 Flash Reasoning costs about $29.48. Gemini 3 Flash Reasoning is roughly 12% cheaper than Claude 3.7 Sonnet Max. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Both models list a 128,000-token context window. That is enough for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude 3.7 Sonnet Max wins 6, Gemini 3 Flash Reasoning wins 6, and 0 are tied. The two models are effectively tied on the index average at 83.7.
The price picture favours Gemini 3 Flash Reasoning. The context picture is effectively a tie. 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 Reasoning if cost is the constraint and Claude 3.7 Sonnet Max if context is the constraint. Test both on a sample of your own traffic before committing.
Choose Claude 3.7 Sonnet Max if
- You prefer Anthropic's tooling or already use it.
Choose Gemini 3 Flash Reasoning if
- Unit cost matters and you want the cheaper blended price.
FAQ
Is Claude 3.7 Sonnet Max better than Gemini 3 Flash Reasoning?
The two models are effectively tied on the index average at 83.7. The better choice depends on price, context and your task. Claude 3.7 Sonnet Max wins 6 benchmarks, Gemini 3 Flash Reasoning wins 6.
Which is cheaper, Claude 3.7 Sonnet Max or Gemini 3 Flash Reasoning?
Gemini 3 Flash Reasoning is cheaper on a blended 3:1 basis at about $29.48 per million tokens, versus $33.46 for Claude 3.7 Sonnet Max.
Which has the larger context window?
Both models list a 128,000-token context window.
Are these models open weights?
Claude 3.7 Sonnet Max is proprietary; Gemini 3 Flash Reasoning is proprietary.
Which should I choose for production?
If you need a single default, start with Gemini 3 Flash Reasoning if cost is the constraint and Claude 3.7 Sonnet Max if context is the constraint. Test both on a sample of your own traffic before committing.