API cost decision in 10 seconds

Nano Banana 2 (Gemini 3.1 Flash Image Preview) vs Gemini 3.1 Pro Preview

Pick Nano Banana 2 (Gemini 3.1 Flash Image Preview) for lower cost; pick Gemini 3.1 Pro Preview only if the larger context window matters more.

Pricing data updated: 2026-05-26T11:08:00Z Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick Nano Banana 2 (Gemini 3.1 Flash Image Preview) for lower cost; pick Gemini 3.1 Pro Preview only if the larger context window matters more.

On the standard 1M input plus 500K output workload, Nano Banana 2 (Gemini 3.1 Flash Image Preview) is estimated at $2 vs $8 for Gemini 3.1 Pro Preview, saving $6 (75% lower).

Cost-first pickNano Banana 2 (Gemini 3.1 Flash Image Preview)

Context-first pickGemini 3.1 Pro Preview

Sample savings$675%

10x traffic gap$60

Gemini 3.1 Pro Preview has more context, but Nano Banana 2 (Gemini 3.1 Flash Image Preview) saves $6 on the standard workload. 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

Same prices, different token mixes.

Nano Banana 2 (Gemini 3.1 Flash Image Preview) stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shape	Token mix	Better pick	Nano Banana 2 (Gemini 3.1 Flash Image Preview)	Gemini 3.1 Pro Preview
Input-heavy / RAG	5M input + 500K output	Nano Banana 2 (Gemini 3.1 Flash Image Preview)	$4	$16
Balanced workload	1M input + 1M output	Nano Banana 2 (Gemini 3.1 Flash Image Preview)	$3.5	$14
Output-heavy chatbot	1M input + 5M output	Nano Banana 2 (Gemini 3.1 Flash Image Preview)	$15.5	$62

Cheaper input Nano Banana 2 (Gemini 3.1 Flash Image Preview) $0.5 vs $2 / 1M

Nano Banana 2 (Gemini 3.1 Flash Image Preview) is $1.5 cheaper per 1M input tokens (75% lower; 4x difference).

Cheaper output Nano Banana 2 (Gemini 3.1 Flash Image Preview) $3 vs $12 / 1M

Nano Banana 2 (Gemini 3.1 Flash Image Preview) is $9 cheaper per 1M output tokens (75% lower; 4x difference).

Larger context Gemini 3.1 Pro Preview 131.07K vs 1.05M

Gemini 3.1 Pro Preview has 917.5K more context (8x larger).

Sample workload Nano Banana 2 (Gemini 3.1 Flash Image Preview) $2 vs $8

Nano Banana 2 (Gemini 3.1 Flash Image Preview) is $6 cheaper on the standard workload (75% lower).

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.

Monthly input tokens Monthly output tokens

Nano Banana 2 (Gemini 3.1 Flash Image Preview) Calculating… Estimated API cost

Gemini 3.1 Pro Preview Calculating… Estimated API cost

Cheaper for this workload Calculating… Difference: calculating…

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

Verdict

Nano Banana 2 (Gemini 3.1 Flash Image Preview) has the lower input price; Nano Banana 2 (Gemini 3.1 Flash Image Preview) has the lower output price; Gemini 3.1 Pro Preview offers the larger context window. For the 1M input plus 500K output sample, Nano Banana 2 (Gemini 3.1 Flash Image Preview) is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $2 for Nano Banana 2 (Gemini 3.1 Flash Image Preview) and $8 for Gemini 3.1 Pro Preview.

Best Fit

Choose Nano Banana 2 (Gemini 3.1 Flash Image Preview) when you care most about lower input-token price, and lower output-token price.

Choose Gemini 3.1 Pro Preview when you care most about larger context window.

Decision Notes

On the standard 1M input plus 500K output workload, Nano Banana 2 (Gemini 3.1 Flash Image Preview) is estimated at $2 vs $8 for Gemini 3.1 Pro Preview, saving $6 (75% lower).
Nano Banana 2 (Gemini 3.1 Flash Image Preview) is $6 cheaper on the standard workload (75% lower).
Nano Banana 2 (Gemini 3.1 Flash Image Preview) is $1.5 cheaper per 1M input tokens (75% lower; 4x difference).
Nano Banana 2 (Gemini 3.1 Flash Image Preview) is $9 cheaper per 1M output tokens (75% lower; 4x difference).
Gemini 3.1 Pro Preview has 917.5K more context (8x larger).

Head-to-Head Specs

Feature	Nano Banana 2 (Gemini 3.1 Flash Image Preview) (Google)	Gemini 3.1 Pro Preview (Google)
Input Price prompt tokens per 1M	$0.5	$2
Completion Price per 1M tokens	$3	$12
Sample Workload Cost 1M input + 500K output	$2	$8
Context Window	131.07K	1.05M
Release Date	2026-02-26	2026-02-19

Use-Case Decision Matrix

Use case	Better pick	Why
Budget-constrained production	Nano Banana 2 (Gemini 3.1 Flash Image Preview)	On the standard 1M input plus 500K output workload, Nano Banana 2 (Gemini 3.1 Flash Image Preview) is estimated at $2 vs $8 for Gemini 3.1 Pro Preview, saving $6 (75% lower).
High-volume input processing	Nano Banana 2 (Gemini 3.1 Flash Image Preview)	Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbots	Nano Banana 2 (Gemini 3.1 Flash Image Preview)	Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document work	Gemini 3.1 Pro Preview	A larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps

Gemma 4 26B A4B (free) can replace Nano Banana 2 (Gemini 3.1 Flash Image Preview) when lower sample workload cost matters most: $0.
Gemma 4 31B (free) can replace Nano Banana 2 (Gemini 3.1 Flash Image Preview) when lower sample workload cost matters most: $0.
Lyria 3 Pro Preview can replace Nano Banana 2 (Gemini 3.1 Flash Image Preview) when lower sample workload cost matters most: $0.
Lyria 3 Clip Preview can replace Nano Banana 2 (Gemini 3.1 Flash Image Preview) when lower sample workload cost matters most: $0.

Larger context near this budget

Llama 4 Scout offers 10M context with $0.23 sample workload cost.
Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
Grok 4.20 offers 2M context with $2.5 sample workload cost.
GPT-5.4 offers 1.05M context with $10 sample workload cost.

Popular competitors

No popular competitor is currently available.

Cheaper alternatives

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Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

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Provider catalogs

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Google catalog

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Nano Banana 2 (Gemini 3.1 Flash Image Preview)

Gemini 3.1 Flash Image Preview, 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...

Gemini 3.1 Pro Preview

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...