DeepSeek V4 Pro vs Gemini 3.5 Flash — LLM API Cost Comparison
Compare DeepSeek V4 Pro (DeepSeek) 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
- $1.74/1M tokens
- Output
- $3.48/1M tokens
- Context
- 1M tokens
- Released
- 2026-03
DeepSeek flagship; 1M context; promo 75% off ($0.435/$0.87) until May 31 2026
- 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 | DeepSeek V4 Pro | Gemini 3.5 Flash | Cheaper by |
|---|---|---|---|
| Light (1M tokens) | $2.26 | $3.75 | DeepSeek V4 Pro (40%) |
| Moderate (10M tokens) | $22.62 | $37.50 | DeepSeek V4 Pro (40%) |
| Heavy (100M tokens) | $226 | $375 | DeepSeek V4 Pro (40%) |
| Very Heavy (1B tokens) | $2,262 | $3,750 | DeepSeek V4 Pro (40%) |
Frequently Asked Questions
Which is cheaper — DeepSeek V4 Pro or Gemini 3.5 Flash?
For input tokens, Gemini 3.5 Flash is cheaper at $1.5/1M tokens — 1.2× less than $1.74/1M. For output tokens, DeepSeek V4 Pro wins at $3.48/1M vs $9/1M. At heavy workloads (100M tokens/month), the cost difference can be significant.
What is the context window difference between DeepSeek V4 Pro and Gemini 3.5 Flash?
DeepSeek V4 Pro supports 1,000,000 tokens per request; Gemini 3.5 Flash supports 1,000,000 tokens. DeepSeek V4 Pro wins on context length, making it better for long documents, large codebases, or extended conversations without chunking.
When should I choose DeepSeek V4 Pro over Gemini 3.5 Flash?
Choose DeepSeek V4 Pro (DeepSeek) if you prefer DeepSeek's ecosystem, tooling, or reliability track record. DeepSeek flagship; 1M context; promo 75% off ($0.435/$0.87) until May 31 2026. 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 DeepSeek V4 Pro vs Gemini 3.5 Flash?
At 700M input + 300M output tokens (1B total): DeepSeek V4 Pro costs $2262; Gemini 3.5 Flash costs $3750. The difference is $1488/billion tokens at this 70/30 input/output ratio.