Head-to-head
DeepSeek-V4-Pro vs Gemini 3.5 Flash
Compare DeepSeek-V4-Pro and Gemini 3.5 Flash on the metrics that decide an agent workload.
| Metric | DeepSeek-V4-Pro | Gemini 3.5 Flash |
|---|---|---|
| Provider | Fireworks AI | Google Gemini |
| Input / 1M | $1.74 | $1.50 |
| Output / 1M | $3.48 | $9.00 |
| Cache read / 1M | $0.14 (−92%) | $0.15 (−90%) |
| Reuse-adj @55% | $1.52 | $2.82 |
| Context | 1M | 1M |
| Cache capture | 81% | 85% |
| Warm TTFT | 130ms (−63%) | 150ms (−61%) |
| Quality index | 86 | 94 |
Teal marks the better value in each row. Reuse-adjusted assumes 55% prefix reuse and a 25% output share.
Pick DeepSeek-V4-Pro when it is cheaper once prefix reuse is priced in, it answers faster on warm cache hits, it is open-weights for on-prem and regulated lanes.
Pick Gemini 3.5 Flash when it scores higher on the composite quality index, it carries the larger 1M context window, it captures more of the available reuse.
Gemini 3.5 Flash leads on quality while DeepSeek-V4-Pro leads on reuse-adjusted cost. Send latency- and budget-sensitive volume to DeepSeek-V4-Pro and reserve Gemini 3.5 Flash for the hard requests. Zumik's aliases route between them automatically under policy.
Frequently asked
DeepSeek-V4-Pro vs Gemini 3.5 Flash, answered.
Is DeepSeek-V4-Pro or Gemini 3.5 Flash cheaper?
At 55% prefix reuse, DeepSeek-V4-Pro blends to about $1.52 per 1M tokens and Gemini 3.5 Flash to about $2.82. DeepSeek-V4-Pro is cheaper on that basis.
Which has the larger context window?
Gemini 3.5 Flash has the larger window: 1M vs 1M tokens.
Which captures more reuse?
Gemini 3.5 Flash shows higher measured cache capture (85% vs 81%) in the Zumik corpus.
Let an alias pick for you.
Route to whichever model wins under current policy automatically. Zumik resolves the alias to the best fit per request, so you never hard-code a loser.