Gemini 3.5 Flash vs Claude Sonnet 4.6: utility speed vs reasoning tier costs
Gemini 3.5 Flash is significantly cheaper and should be used for simple classification, routing, and high-frequency tasks. Claude Sonnet 4.6 is ideal when superior reasoning is required.
Speedy utility model versus premium reasoning flagship.
Comparing a high-speed utility model like Gemini 3.5 Flash with a premium flagship like Claude Sonnet 4.6 helps optimize your project's price-to-performance ratio.
By TechCompare · Updated
Cost Comparison
Based on 100,000 input tokens (50% cached), 5,000 output tokens, and 100 requests.Provider USD token rates. Cache storage, cache writes, and other service fees aren't included.
Side-by-side specs
| Spec | Gemini 3.5 Flash | Claude Sonnet 4.6 |
|---|---|---|
| Input cost per 1M tokens | $1.50 (better on this spec) | $3.00 |
| Output cost per 1M tokens | $9.00 (better on this spec) | $15.00 |
| Cache reads per 1M tokens | $0.15 (better on this spec) | $0.30 |
| Batch discount | 50% | 50% |
How they differ
Gemini 3.5 Flash charges $1.50/M input, $9/M output, and $0.15/M cache reads. Claude Sonnet 4.6 charges $3/M input, $15/M output, and $0.30/M cache reads. Both cache-read discounts are 90%, and both offer 50% batch token discounts. Google cache storage and Anthropic cache writes are additional charges. These official USD token rates were checked on October 7, 2026.
Verdict
Gemini costs 50% less on uncached input and cache reads, and 40% less on output. For 100K input, half cached, and 5K output, Gemini costs $0.1275 versus $0.24 on Sonnet before cache storage, cache writes, or other service charges. Shared 50% batch discounts preserve the token-price ratios. Choose using task results and full billed usage rather than price alone.
Which should you pick?
Choose Gemini 3.5 Flash
Simple routing, sorting, text extraction, and high-speed API endpoints.
Choose Claude Sonnet 4.6
Software engineering, multi-step logic analysis, and advanced customer agents.