Gemini 3.1 Flash-Lite vs DeepSeek V4-Pro
Google's Gemini 3.1 Flash-Lite and DeepSeek's DeepSeek V4-Pro 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
Gemini 3.1 Flash-Lite is the cheaper option — roughly 1.8x less on a blended workload, and it suits ultra-cheap high-volume tasks. DeepSeek V4-Pro justifies its premium when you need frontier-adjacent reasoning at open-weight prices. Only DeepSeek V4-Pro does native reasoning, which matters for multi-step tasks but adds billable thinking tokens.
Google • Gemini 3.1
$0.25 / $1.50
/ 1M tokens (input / output)
Google's efficiency tier and a long-term stable target, priced for workloads measured in millions of calls rather than thousands. It gives up the deeper reasoning of 3.5 Flash, so it suits mechanical tasks — classification, extraction, moderation — where a million tokens of context still helps but chain-of-thought does not.
DeepSeek • DeepSeek V4
$0.66 / $1.98
/ 1M tokens (input / output)
A 1.6T-parameter mixture-of-experts model with 49B active, released under MIT and callable through DeepSeek's own API with configurable reasoning effort. Since 16 August 2026 DeepSeek bills on a peak/off-peak schedule, so the hour you run a job changes the bill by exactly 2x — which makes it unusually well suited to scheduled batch work.
Input price
DeepSeek V4-Pro is 2.6x the price than Gemini 3.1 Flash-Lite on input tokens.
Output price
DeepSeek V4-Pro is 32% more expensive than Gemini 3.1 Flash-Lite 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 Flash-Lite | DeepSeek V4-Pro | Difference |
|---|---|---|---|
| Light — 1M in / 200K out | $1 | $1 | $1 |
| Moderate — 10M in / 2M out | $6 | $11 | $5 |
| Heavy — 100M in / 20M out | $55 | $106 | $51 |
Specification comparison
| Attribute | Gemini 3.1 Flash-Lite | DeepSeek V4-Pro |
|---|---|---|
| Input (/ 1M tokens) | $0.25 | $0.66 |
| Output (/ 1M tokens) | $1.50 | $1.98 |
| Cached input | — | $0.02 |
| Context window | 1,048,576 tokens | 1,000,000 tokens |
| Max output | 65,536 tokens | 131,072 tokens |
| Native reasoning | No | Yes |
| Knowledge cutoff | 2025-01 | 2026-03 |
| Relative latency | low | medium |
| Open weights | No | MIT |
| API model ID | gemini-3.1-flash-lite | deepseek-v4-pro |
| Status | stable | stable |
DeepSeek V4-Pro: Off-peak rate shown. Peak rates are exactly double ($1.32 input / $3.96 output) during 01:00–04:00 and 06:00–10:00 UTC, Monday to Friday. Cache hits cost roughly 3% of a cache miss.
Choose Gemini 3.1 Flash-Lite if…
- Content moderation at volume
- Classification and routing
- Lightweight summarization
- Cheap long-context retrieval
Choose DeepSeek V4-Pro if…
- Overnight batch reasoning jobs
- Self-hosted deployments needing MIT terms
- Cost-sensitive coding agents
- Chinese-language workloads
Frequently asked
Is Gemini 3.1 Flash-Lite or DeepSeek V4-Pro cheaper?
Gemini 3.1 Flash-Lite is cheaper. On a blended 3:1 input-to-output workload it costs about 1.8x less than DeepSeek V4-Pro.
Which has the larger context window, Gemini 3.1 Flash-Lite or DeepSeek V4-Pro?
Gemini 3.1 Flash-Lite has the larger window at 1.05M tokens versus 1M.
Should I use Gemini 3.1 Flash-Lite or DeepSeek V4-Pro?
Pick Gemini 3.1 Flash-Lite for ultra-cheap high-volume tasks. Pick DeepSeek V4-Pro for frontier-adjacent reasoning at open-weight prices. If cost dominates the decision, Gemini 3.1 Flash-Lite wins; if you need the capability ceiling, benchmark both on your own evals before committing.