Claude Sonnet 4.6 vs Gemini 3.5 Flash — LLM API Cost Comparison
Compare Claude Sonnet 4.6 (Anthropic) vs Gemini 3.5 Flash (Google) on cost per million tokens, context window, and monthly spend.
Prices verified 2026-05-23 · Pricing may change — use the calculator for current estimates
- Input
- $3/1M tokens
- Output
- $15/1M tokens
- Context
- 1M tokens
- Released
- 2026-04
Best speed/intelligence balance; extended thinking supported
- Input
- $1.5/1M tokens
- Output
- $9/1M tokens
- Context
- 1M tokens
- Released
- 2026-05
Latest Gemini; frontier intelligence + superior search & grounding
Monthly Cost by Usage Tier (70% input / 30% output ratio)
| Usage | Claude Sonnet 4.6 | Gemini 3.5 Flash | Cheaper by |
|---|---|---|---|
| Light (1M tokens) | $6.60 | $3.75 | Gemini 3.5 Flash (43%) |
| Moderate (10M tokens) | $66.00 | $37.50 | Gemini 3.5 Flash (43%) |
| Heavy (100M tokens) | $660 | $375 | Gemini 3.5 Flash (43%) |
| Very Heavy (1B tokens) | $6,600 | $3,750 | Gemini 3.5 Flash (43%) |
Frequently Asked Questions
Which is cheaper — Claude Sonnet 4.6 or Gemini 3.5 Flash?
For input tokens, Gemini 3.5 Flash is cheaper at $1.5/1M tokens — 2.0× less than $3/1M. For output tokens, Gemini 3.5 Flash wins at $9/1M vs $15/1M. At heavy workloads (100M tokens/month), the cost difference can be significant.
What is the context window difference between Claude Sonnet 4.6 and Gemini 3.5 Flash?
Claude Sonnet 4.6 supports 1,000,000 tokens per request; Gemini 3.5 Flash supports 1,000,000 tokens. Claude Sonnet 4.6 wins on context length, making it better for long documents, large codebases, or extended conversations without chunking.
When should I choose Claude Sonnet 4.6 over Gemini 3.5 Flash?
Choose Claude Sonnet 4.6 (Anthropic) if you prefer Anthropic's ecosystem, tooling, or reliability track record. Best speed/intelligence balance; extended thinking supported. Choose Gemini 3.5 Flash (Google) if Latest Gemini; frontier intelligence + superior search & grounding. the price/performance fits your workload better. Use this calculator to find the break-even point for your exact token volume.
How much does 1 billion tokens cost on Claude Sonnet 4.6 vs Gemini 3.5 Flash?
At 700M input + 300M output tokens (1B total): Claude Sonnet 4.6 costs $6600; Gemini 3.5 Flash costs $3750. The difference is $2850/billion tokens at this 70/30 input/output ratio.