Choosing between DeepSeek-V4-Pro (DeepSeek) and Gemini 3.5 Flash (Google)? This is a side-by-side of their API pricing, context windows, and real cost on a sample workload — so you can pick on the numbers, not the marketing.
DeepSeek-V4-Pro vs Gemini 3.5 Flash: pricing & specs
| DeepSeek-V4-Pro | Gemini 3.5 Flash | |
|---|---|---|
| Vendor | DeepSeek | |
| Input / 1M tokens | $0.435 | $1.50 |
| Output / 1M tokens | $0.87 | $9.00 |
| Cached input / 1M | $0.0036 | — |
| Context window | 128K tokens | 1M tokens |
DeepSeek-V4-Pro: Standard cache-miss input pricing; off-peak discounts may apply.
Cost example: 1M input + 1M output tokens
For a workload of 1M input plus 1M output tokens, DeepSeek-V4-Pro costs $1.305 and Gemini 3.5 Flash costs $10.50 — DeepSeek-V4-Pro is about 88% cheaper on this mix. Your real ratio of input to output tokens shifts the math; plug in your own numbers with the token cost calculator.
Which should you choose?
- Lower cost: DeepSeek-V4-Pro is cheaper on output tokens ($0.87 vs $9.00 / 1M), which usually dominates spend on generation-heavy workloads.
- Larger context window: Gemini 3.5 Flash fits more in one prompt (1M tokens) — better for long documents or big RAG context.
- Ecosystem: pick the provider whose SDK, rate limits, and tooling fit your stack — see DeepSeek rate limits and Google rate limits.
Full specs: DeepSeek-V4-Pro · Gemini 3.5 Flash. Thinking of switching providers? See the migration guides.
Prices as of June 2026 and change often — verify before relying on them.