Claude Sonnet 4.5 Vision vs Gemini 3 Flash Turbo: which model should you choose?
We compared Claude Sonnet 4.5 Vision and Gemini 3 Flash Turbo on price, context window and 12 benchmarks. Gemini 3 Flash Turbo has the stronger average benchmark score; Gemini 3 Flash Turbo is cheaper on a blended 3:1 basis.
Claude Sonnet 4.5 Vision
Claude Sonnet 4.5 Vision is a frontier model from Anthropic. It offers a 128,000-token context window, costs $16.99 per million input tokens and $82.33 per million output tokens, and averages 83.8 across the index's benchmark suite.
- Input
- $16.99 / 1M
- Output
- $82.33 / 1M
- Context
- 128,000
- Avg score
- 83.8
- Open weights
- No
Gemini 3 Flash Turbo
Gemini 3 Flash Turbo is a frontier model from Google DeepMind. It offers a 200,000-token context window, costs $17.07 per million input tokens and $69.05 per million output tokens, and averages 84.1 across the index's benchmark suite.
- Input
- $17.07 / 1M
- Output
- $69.05 / 1M
- Context
- 200,000
- Avg score
- 84.1
- Open weights
- No
Specification comparison
| Spec | Claude Sonnet 4.5 Vision | Gemini 3 Flash Turbo | Edge |
|---|---|---|---|
| Input price / 1M | $16.99 | $17.07 | A |
| Output price / 1M | $82.33 | $69.05 | B |
| Context window | 128,000 | 200,000 | B |
| Max output | 16,384 | 16,384 | Tie |
| Average score | 83.8 | 84.1 | B |
| Arena Elo | 1447.6 | 1473.4 | B |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Sonnet 4.5 Vision wins 5, Gemini 3 Flash Turbo wins 7, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Sonnet 4.5 Vision | Gemini 3 Flash Turbo | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 84.8 | 87.9 | 3.1 | Gemini 3 Flash Turbo |
| GPQA Diamond | 79.6 | 77.5 | 2.1 | Claude Sonnet 4.5 Vision |
| SWE-bench Verified | 73.7 | 72.5 | 1.2 | Claude Sonnet 4.5 Vision |
| HumanEval | 87.0 | 90.6 | 3.6 | Gemini 3 Flash Turbo |
| MATH-500 | 90.6 | 87.6 | 3.0 | Claude Sonnet 4.5 Vision |
| AIME 2025 | 86.4 | 81.3 | 5.1 | Claude Sonnet 4.5 Vision |
| LiveCodeBench | 76.5 | 78.5 | 2.0 | Gemini 3 Flash Turbo |
| IFEval | 89.9 | 88.9 | 1.0 | Claude Sonnet 4.5 Vision |
| TruthfulQA | 83.7 | 87.4 | 3.7 | Gemini 3 Flash Turbo |
| HellaSwag | 89.4 | 89.5 | 0.1 | Gemini 3 Flash Turbo |
| MMMU | 79.7 | 83.0 | 3.3 | Gemini 3 Flash Turbo |
| Arena Elo | 1447.6 | 1473.4 | 25.8 | Gemini 3 Flash Turbo |
Price analysis
On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 Vision costs about $33.33 per million tokens and Gemini 3 Flash Turbo costs about $30.06. Gemini 3 Flash Turbo is roughly 10% cheaper than Claude Sonnet 4.5 Vision. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Gemini 3 Flash Turbo has the larger context window at 200,000 tokens, compared with 128,000 for Claude Sonnet 4.5 Vision. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Sonnet 4.5 Vision wins 5, Gemini 3 Flash Turbo wins 7, and 0 are tied. On the index average, Gemini 3 Flash Turbo leads Claude Sonnet 4.5 Vision by 0.3 points (84.1 versus 83.8).
The price picture favours Gemini 3 Flash Turbo. The context picture favours Gemini 3 Flash Turbo. 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 Turbo for quality-sensitive work, and check whether its price holds at your expected volume before committing.
Choose Claude Sonnet 4.5 Vision if
- You prefer Anthropic's tooling or already use it.
Choose Gemini 3 Flash Turbo 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 200,000-token context window.
FAQ
Is Claude Sonnet 4.5 Vision better than Gemini 3 Flash Turbo?
On the index average, Gemini 3 Flash Turbo leads Claude Sonnet 4.5 Vision by 0.3 points (84.1 versus 83.8). The better choice depends on price, context and your task. Claude Sonnet 4.5 Vision wins 5 benchmarks, Gemini 3 Flash Turbo wins 7.
Which is cheaper, Claude Sonnet 4.5 Vision or Gemini 3 Flash Turbo?
Gemini 3 Flash Turbo is cheaper on a blended 3:1 basis at about $30.06 per million tokens, versus $33.33 for Claude Sonnet 4.5 Vision.
Which has the larger context window?
Gemini 3 Flash Turbo has the larger context window at 200,000 tokens. Claude Sonnet 4.5 Vision has 128,000 tokens.
Are these models open weights?
Claude Sonnet 4.5 Vision is proprietary; Gemini 3 Flash Turbo is proprietary.
Which should I choose for production?
If you need a single default, start with Gemini 3 Flash Turbo for quality-sensitive work, and check whether its price holds at your expected volume before committing.