Claude Sonnet 4.6 vs Gemini 3.5 Flash
Detailed comparison of API pricing, technical specifications, and benchmark scores. Updated 2026-06-29.
Cost at a Glance
Claude Sonnet 4.6 is 10.6× more expensive than Gemini 3.5 Flash — switching could save 90.6% on your monthly API bill.
At 5M input + 2M output tokens per month:
Choosing Gemini 3.5 Flash could save you $40.75/mo
Price Comparison (per 1M tokens)
| Metric | Claude Sonnet 4.6 | Gemini 3.5 Flash |
|---|---|---|
| Input (per 1M tokens) | $3.00 | $0.25 |
| Output (per 1M tokens) | $15.00 | $1.50 |
| Cache Write (per 1M tokens) | $3.75 | — |
| Cache Read (per 1M tokens) | $0.30 | $0.03 |
| Batch Input (per 1M tokens) | $1.50 | — |
| Batch Output (per 1M tokens) | $7.50 | — |
Prices are per 1 million tokens. Actual costs depend on your monthly token volume. Use the calculator →
Specifications
| Spec | Claude Sonnet 4.6 | Gemini 3.5 Flash |
|---|---|---|
| Context Window | 1M | 1M |
| Max Output Tokens | 128K | 64K |
| Knowledge Cutoff | 2026-03 | 2026-04 |
| Modalities | Text, Image | Text, Image |
| Prompt Caching | Yes | Yes |
| Batch API | Yes | No |
| Thinking / Reasoning | Yes | No |
Benchmark Scores
| Benchmark | Claude Sonnet 4.6 | Gemini 3.5 Flash |
|---|---|---|
| SWE-bench Verified | 79.6 | 65.0 |
| MMLU-Pro | 85.2 | 80.0 |
| HumanEval | 94.1 | 90.0 |
Benchmark scores from official provider reports. Higher is better. Missing scores indicate the provider has not published that benchmark yet.
Use Cases
Claude Sonnet 4.6
Gemini 3.5 Flash
About the Providers
Claude Sonnet 4.6 is developed by Anthropic. Gemini 3.5 Flash is developed by Google. This is a cross-provider comparison between Anthropic and Google models. For the most up-to-date pricing, always check the official API documentation from each provider.