Claude Sonnet 4.5 vs Gemini 3 Pro Vision: which model should you choose?
We compared Claude Sonnet 4.5 and Gemini 3 Pro Vision on price, context window and 12 benchmarks. Claude Sonnet 4.5 has the stronger average benchmark score; Gemini 3 Pro Vision is cheaper on a blended 3:1 basis.
Claude Sonnet 4.5
Claude Sonnet 4.5 is a frontier model from Anthropic. It offers a 400,000-token context window, costs $17.84 per million input tokens and $70.50 per million output tokens, and averages 86.0 across the index's benchmark suite.
- Input
- $17.84 / 1M
- Output
- $70.50 / 1M
- Context
- 400,000
- Avg score
- 86.0
- Open weights
- No
Gemini 3 Pro Vision
Gemini 3 Pro Vision is a frontier model from Google DeepMind. It offers a 200,000-token context window, costs $17.59 per million input tokens and $68.83 per million output tokens, and averages 85.5 across the index's benchmark suite.
- Input
- $17.59 / 1M
- Output
- $68.83 / 1M
- Context
- 200,000
- Avg score
- 85.5
- Open weights
- No
Specification comparison
| Spec | Claude Sonnet 4.5 | Gemini 3 Pro Vision | Edge |
|---|---|---|---|
| Input price / 1M | $17.84 | $17.59 | B |
| Output price / 1M | $70.50 | $68.83 | B |
| Context window | 400,000 | 200,000 | A |
| Max output | 128,000 | 128,000 | Tie |
| Average score | 86.0 | 85.5 | A |
| Arena Elo | 1478.2 | 1458.1 | A |
| Open weights | No | No | Tie |
Benchmark comparison
Claude Sonnet 4.5 wins 8, Gemini 3 Pro Vision wins 4, and 0 benchmarks are tied. The table shows the modelled score for each model and the gap.
| Benchmark | Claude Sonnet 4.5 | Gemini 3 Pro Vision | Gap | Winner |
|---|---|---|---|---|
| MMLU-Pro | 88.0 | 87.3 | 0.7 | Claude Sonnet 4.5 |
| GPQA Diamond | 82.6 | 80.6 | 2.0 | Claude Sonnet 4.5 |
| SWE-bench Verified | 74.2 | 76.5 | 2.3 | Gemini 3 Pro Vision |
| HumanEval | 92.7 | 91.6 | 1.1 | Claude Sonnet 4.5 |
| MATH-500 | 87.0 | 88.4 | 1.4 | Gemini 3 Pro Vision |
| AIME 2025 | 86.3 | 87.3 | 1.0 | Gemini 3 Pro Vision |
| LiveCodeBench | 82.5 | 79.2 | 3.3 | Claude Sonnet 4.5 |
| IFEval | 91.1 | 90.4 | 0.7 | Claude Sonnet 4.5 |
| TruthfulQA | 87.2 | 84.5 | 2.7 | Claude Sonnet 4.5 |
| HellaSwag | 93.0 | 91.1 | 1.9 | Claude Sonnet 4.5 |
| MMMU | 80.9 | 83.6 | 2.7 | Gemini 3 Pro Vision |
| Arena Elo | 1478.2 | 1458.1 | 20.1 | Claude Sonnet 4.5 |
Price analysis
On a blended 3:1 input-to-output basis, Claude Sonnet 4.5 costs about $31.00 per million tokens and Gemini 3 Pro Vision costs about $30.40. Gemini 3 Pro Vision is roughly 2% cheaper than Claude Sonnet 4.5. At high volume, that gap compounds quickly, so price should carry real weight unless the quality difference is decisive.
Claude Sonnet 4.5 has the larger context window at 400,000 tokens, compared with 200,000 for Gemini 3 Pro Vision. That matters for long documents, large codebases and multi-step agent traces.
Verdict
Across 12 shared benchmarks, Claude Sonnet 4.5 wins 8, Gemini 3 Pro Vision wins 4, and 0 are tied. On the index average, Claude Sonnet 4.5 leads Gemini 3 Pro Vision by 0.5 points (86.0 versus 85.5).
The price picture favours Gemini 3 Pro Vision. The context picture favours Claude Sonnet 4.5. 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 Sonnet 4.5 for quality-sensitive work and Gemini 3 Pro Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.
Choose Claude Sonnet 4.5 if
- You want the higher average benchmark score in this index.
- You need the larger 400,000-token context window.
Choose Gemini 3 Pro Vision if
- Unit cost matters and you want the cheaper blended price.
FAQ
Is Claude Sonnet 4.5 better than Gemini 3 Pro Vision?
On the index average, Claude Sonnet 4.5 leads Gemini 3 Pro Vision by 0.5 points (86.0 versus 85.5). The better choice depends on price, context and your task. Claude Sonnet 4.5 wins 8 benchmarks, Gemini 3 Pro Vision wins 4.
Which is cheaper, Claude Sonnet 4.5 or Gemini 3 Pro Vision?
Gemini 3 Pro Vision is cheaper on a blended 3:1 basis at about $30.40 per million tokens, versus $31.00 for Claude Sonnet 4.5.
Which has the larger context window?
Claude Sonnet 4.5 has the larger context window at 400,000 tokens. Gemini 3 Pro Vision has 200,000 tokens.
Are these models open weights?
Claude Sonnet 4.5 is proprietary; Gemini 3 Pro Vision is proprietary.
Which should I choose for production?
If you need a single default, start with Claude Sonnet 4.5 for quality-sensitive work and Gemini 3 Pro Vision for high-volume, well-scoped tasks. Run both on a sample of your own traffic before locking in a choice.