API cost decision in 10 seconds
Gemini 3.1 Pro Preview vs 🔥Gemini 3 Flash Preview
Pick Gemini 3 Flash Preview when budget is the priority.
Pricing data updated:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick Gemini 3 Flash Preview when budget is the priority.
On the standard 1M input plus 500K output workload, Gemini 3 Flash Preview is estimated at $2 vs $8 for Gemini 3.1 Pro Preview, saving $6 (75% lower).
Cost-first pickGemini 3 Flash Preview
Context-first pickTie
Sample savings$675%
10x traffic gap$60
The reported context window is tied, so cost and provider fit carry more weight. At 10x that traffic, the same price gap is about $60. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Gemini 3 Flash Preview stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | Gemini 3.1 Pro Preview | Gemini 3 Flash Preview |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | Gemini 3 Flash Preview | $16 | $4 |
| Balanced workload | 1M input + 1M output | Gemini 3 Flash Preview | $14 | $3.5 |
| Output-heavy chatbot | 1M input + 5M output | Gemini 3 Flash Preview | $62 | $15.5 |
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
Gemini 3 Flash Preview has the lower input price, Gemini 3 Flash Preview has the lower output price, and Tie offers the larger context window.
For a 1M input token plus 500K output token workload, the estimated API cost is $8 for Gemini 3.1 Pro Preview and $2 for Gemini 3 Flash Preview.
Choose Gemini 3.1 Pro Preview when its provider, model quality, latency, or availability is more important than the numeric price/context winner.
Choose Gemini 3 Flash Preview when you care most about lower input-token price, and lower output-token price.
| Feature | Gemini 3.1 Pro Preview (Google) | 🔥Gemini 3 Flash Preview (Google) |
|---|---|---|
| Input Price prompt tokens per 1M | $2 | $0.5 |
| Completion Price per 1M tokens | $12 | $3 |
| Sample Workload Cost 1M input + 500K output | $8 | $2 |
| Context Window | 1.05M | 1.05M |
| Release Date | 2026-02-19 | 2025-12-17 |
| Popularity | #7 |
Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation...
Gemini 3 Flash Preview is a high speed, high value thinking model designed for agentic workflows, multi turn chat, and coding assistance. It delivers near Pro level reasoning and tool...
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | Gemini 3 Flash Preview | On the standard 1M input plus 500K output workload, Gemini 3 Flash Preview is estimated at $2 vs $8 for Gemini 3.1 Pro Preview, saving $6 (75% lower). |
| High-volume input processing | Gemini 3 Flash Preview | Lower prompt-token price matters most when prompts or retrieved passages dominate the bill. |
| Long responses and chatbots | Gemini 3 Flash Preview | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Tie | A larger context window leaves more room for retrieved passages and source files. |