Gemini 3.5 Flash vs DeepSeek V4-Flash
Google's Gemini 3.5 Flash and DeepSeek's DeepSeek V4-Flash both target production language workloads, but they price and behave differently. Here is the side-by-side.
Pricing checked against provider documentation on . How we verify
The short answer
DeepSeek V4-Flash is the cheaper option — roughly 10.2x less on a blended workload, and it suits the cheapest capable open-weight option. Gemini 3.5 Flash justifies its premium when you need agentic loops and sub-agent fleets.
Google • Gemini 3.5
$1.50 / $9.00
/ 1M tokens (input / output)
Google's most capable Flash model, tuned for the agentic era: sub-agent deployment, multi-step workflows, and rapid coding iterations at scale. Supports search grounding, function calling, structured outputs, and computer use in preview. Note that it is pricier than the Gemini 3 Flash preview it replaced.
DeepSeek • DeepSeek V4
$0.22 / $0.66
/ 1M tokens (input / output)
A 284B-parameter MoE with only 13B active, which is why it runs fast and prices low. Notable for a 384K maximum output — far beyond the 128K most frontier models cap at — and for supporting both thinking and non-thinking modes, so you can switch reasoning off on easy requests rather than paying for it.
Input price
DeepSeek V4-Flash is 85% cheaper than Gemini 3.5 Flash on input tokens.
Output price
DeepSeek V4-Flash is 93% cheaper than Gemini 3.5 Flash on output tokens — usually the side that dominates the bill.
Monthly cost at three workload sizes
Standard (non-batch, non-cached) rates. Reasoning models will exceed these figures because thinking tokens bill as output.
| Workload | Gemini 3.5 Flash | DeepSeek V4-Flash | Difference |
|---|---|---|---|
| Light — 1M in / 200K out | $3 | $0 | $3 |
| Moderate — 10M in / 2M out | $33 | $4 | $29 |
| Heavy — 100M in / 20M out | $330 | $35 | $295 |
Specification comparison
| Attribute | Gemini 3.5 Flash | DeepSeek V4-Flash |
|---|---|---|
| Input (/ 1M tokens) | $1.50 | $0.22 |
| Output (/ 1M tokens) | $9.00 | $0.66 |
| Cached input | — | $0.01 |
| Context window | 1,048,576 tokens | 1,000,000 tokens |
| Max output | 65,536 tokens | 384,000 tokens |
| Native reasoning | Yes | Yes |
| Knowledge cutoff | 2025-01 | 2026-03 |
| Relative latency | low | low |
| Open weights | No | MIT |
| API model ID | gemini-3.5-flash | deepseek-v4-flash |
| Status | stable | stable |
Gemini 3.5 Flash: Flat rate at any context length, unlike Gemini 3.1 Pro's 200K cliff.
DeepSeek V4-Flash: Off-peak rate shown. Peak rates double ($0.44 / $1.32) during 01:00–04:00 and 06:00–10:00 UTC on weekdays. Superseded the earlier flat-rate pricing of $0.14 / $0.28 that many comparison sites still quote.
Choose Gemini 3.5 Flash if…
- Sub-agent fleets and orchestration
- Fast coding iteration loops
- Search-grounded answers
- Multimodal ingestion at scale
Choose DeepSeek V4-Flash if…
- High-volume classification and extraction
- Very long generated outputs
- Budget coding agents
- Local deployment on modest hardware
Frequently asked
Is Gemini 3.5 Flash or DeepSeek V4-Flash cheaper?
DeepSeek V4-Flash is cheaper. On a blended 3:1 input-to-output workload it costs about 10.2x less than Gemini 3.5 Flash.
Which has the larger context window, Gemini 3.5 Flash or DeepSeek V4-Flash?
Gemini 3.5 Flash has the larger window at 1.05M tokens versus 1M.
Should I use Gemini 3.5 Flash or DeepSeek V4-Flash?
Pick Gemini 3.5 Flash for agentic loops and sub-agent fleets. Pick DeepSeek V4-Flash for the cheapest capable open-weight option. If cost dominates the decision, DeepSeek V4-Flash wins; if you need the capability ceiling, benchmark both on your own evals before committing.