Gemini 3.1 Pro vs DeepSeek V4-Flash
Google's Gemini 3.1 Pro 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 13.6x less on a blended workload, and it suits the cheapest capable open-weight option. Gemini 3.1 Pro justifies its premium when you need best price-to-reasoning ratio.
Google • Gemini 3.1
$2.00 / $12.00
/ 1M tokens (input / output)
Google's shipping flagship while 3.5 Pro remains unreleased, and the cheapest frontier model by a wide margin. It still tops several hard-reasoning boards including GPQA Diamond and ARC-AGI-2, making it the value choice for research-style workloads — provided you keep prompts under 200K tokens, where the price doubles.
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 89% cheaper than Gemini 3.1 Pro on input tokens.
Output price
DeepSeek V4-Flash is 95% cheaper than Gemini 3.1 Pro 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 3.1 Pro | DeepSeek V4-Flash | Difference |
|---|---|---|---|
| Light — 1M in / 200K out | $4 | $0 | $4 |
| Moderate — 10M in / 2M out | $44 | $4 | $40 |
| Heavy — 100M in / 20M out | $440 | $35 | $405 |
Specification comparison
| Attribute | Gemini 3.1 Pro | DeepSeek V4-Flash |
|---|---|---|
| Input (/ 1M tokens) | $2.00 | $0.22 |
| Output (/ 1M tokens) | $12.00 | $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 | 2025-06 | 2026-03 |
| Relative latency | medium | low |
| Open weights | No | MIT |
| API model ID | gemini-3.1-pro-preview | deepseek-v4-flash |
| Status | preview | stable |
Gemini 3.1 Pro: Prompts over 200K tokens reprice to $4 input / $18 output per 1M.
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 3.1 Pro if…
- Hard reasoning and research tasks
- Long-context document and video analysis
- Native multimodal pipelines
- Cost-conscious frontier workloads
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 3.1 Pro or DeepSeek V4-Flash cheaper?
DeepSeek V4-Flash is cheaper. On a blended 3:1 input-to-output workload it costs about 13.6x less than Gemini 3.1 Pro.
Which has the larger context window, Gemini 3.1 Pro or DeepSeek V4-Flash?
Gemini 3.1 Pro has the larger window at 1.05M tokens versus 1M.
Should I use Gemini 3.1 Pro or DeepSeek V4-Flash?
Pick Gemini 3.1 Pro for best price-to-reasoning ratio. 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.