Solar Pro 4 is $0.47 cheaper per 1M input tokens (94% lower; 16.7x difference).
API cost decision in 10 seconds
Solar Pro 4 vs Nano Banana 2 (Gemini 3.1 Flash Image)
Pick Solar Pro 4 when budget and context both matter.
Page updated:
Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick Solar Pro 4 when budget and context both matter.
On the standard 1M input plus 500K output workload, Solar Pro 4 is estimated at $0.09 vs $2 for Nano Banana 2 (Gemini 3.1 Flash Image), saving $1.91 (95.5% lower).
Cost-first pickSolar Pro 4
Context-first pickSolar Pro 4
Sample savings$1.9195.5%
10x traffic gap$19.1
Solar Pro 4 is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $19.1. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Solar Pro 4 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | Solar Pro 4 | Nano Banana 2 (Gemini 3.1 Flash Image) |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | Solar Pro 4 | $0.21 | $4 |
| Balanced workload | 1M input + 1M output | Solar Pro 4 | $0.15 | $3.5 |
| Output-heavy chatbot | 1M input + 5M output | Solar Pro 4 | $0.63 | $15.5 |
Solar Pro 4 is $2.88 cheaper per 1M output tokens (96% lower; 25x difference).
Solar Pro 4 has 393.22K more context (4x larger).
Solar Pro 4 is $1.91 cheaper on the standard workload (95.5% lower).
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
Solar Pro 4 has the lower input price; Solar Pro 4 has the lower output price; Solar Pro 4 offers the larger context window. For the 1M input plus 500K output sample, Solar Pro 4 is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.09 for Solar Pro 4 and $2 for Nano Banana 2 (Gemini 3.1 Flash Image).
Choose Solar Pro 4 when you care most about lower input-token price, lower output-token price, and larger context window.
Choose Nano Banana 2 (Gemini 3.1 Flash Image) when its provider, model quality, latency, or availability is more important than the numeric price/context winner.
- On the standard 1M input plus 500K output workload, Solar Pro 4 is estimated at $0.09 vs $2 for Nano Banana 2 (Gemini 3.1 Flash Image), saving $1.91 (95.5% lower).
- Solar Pro 4 is $1.91 cheaper on the standard workload (95.5% lower).
- Solar Pro 4 is $0.47 cheaper per 1M input tokens (94% lower; 16.7x difference).
- Solar Pro 4 is $2.88 cheaper per 1M output tokens (96% lower; 25x difference).
- Solar Pro 4 has 393.22K more context (4x larger).
| Feature | Solar Pro 4 (Upstage) | Nano Banana 2 (Gemini 3.1 Flash Image) (Google) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.03 | $0.5 |
| Completion Price per 1M tokens | $0.12 | $3 |
| Sample Workload Cost 1M input + 500K output | $0.09 | $2 |
| Context Window | 524.29K | 131.07K |
| Release Date |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | Solar Pro 4 | On the standard 1M input plus 500K output workload, Solar Pro 4 is estimated at $0.09 vs $2 for Nano Banana 2 (Gemini 3.1 Flash Image), saving $1.91 (95.5% lower). |
| High-volume input processing | Solar Pro 4 | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | Solar Pro 4 | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Solar Pro 4 | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- Gemma 4 26B A4B (free) can replace Nano Banana 2 (Gemini 3.1 Flash Image) when lower sample workload cost matters most: $0.
- Gemma 4 31B (free) can replace Nano Banana 2 (Gemini 3.1 Flash Image) when lower sample workload cost matters most: $0.
- Lyria 3 Pro Preview can replace Nano Banana 2 (Gemini 3.1 Flash Image) when lower sample workload cost matters most: $0.
- Lyria 3 Clip Preview can replace Nano Banana 2 (Gemini 3.1 Flash Image) when lower sample workload cost matters most: $0.
- Grok 4.20 Multi-Agent offers 2M context with $2.5 sample workload cost.
- Grok 4.20 offers 2M context with $2.5 sample workload cost.
- DeepSeek V4 Flash 0731 offers 1.31M context with $0.17 sample workload cost.
- DeepSeek V4 Flash Latest offers 1.31M context with $0.11 sample workload cost.
- DeepSeek V4 Flash 0731 · DeepSeek · #1
- MiMo-V2.5 · Xiaomi · #2
- Hy3 · Tencent · #3
- Ox Alpha · stealth · #4
Cheaper alternatives
Review low-cost models sorted by a standard 1M input plus 500K output workload.
Open cheapest modelsLarger context alternatives
Find models with larger context windows for RAG, long documents, and codebase review.
Open largest context modelsProvider catalogs
Compare models within provider hubs before choosing a final API vendor.
Open provider hubsUpstage catalog
Review all tracked Upstage models before deciding whether this matchup is the right shortlist.
Open Upstage modelsGoogle catalog
Check other Google models with comparable pricing, context, or release timing.
Open Google modelsSolar Pro 4 is Upstage's cost-efficient large language model, featuring a 524K context window. It is built for long-horizon tasks and agentic workflows, with strong capabilities in office productivity, document-intensive...
Gemini 3.1 Flash Image, a.k.a. "Nano Banana 2," is Google’s latest state of the art image generation and editing model, delivering Pro-level visual quality at Flash speed. It combines advanced...