How much does the Nano Banana 2 (Gemini 3.1 Flash Image) API cost?

On FastMetal, Nano Banana 2 (Gemini 3.1 Flash Image) is billed per generated image: $0.078 per image on a US-dollar account, before tax — not per token. Usage is drawn from a prepaid balance; there is no subscription or monthly fee.

Can I call Nano Banana 2 (Gemini 3.1 Flash Image) with the OpenAI SDK?

Yes. Point base_url at https://api.fastmetal.ai/v1 and pass "google-nano-banana-2" as the model; existing OpenAI-style code works unchanged, including streaming, tool calls and structured output.

What is the context window of Nano Banana 2 (Gemini 3.1 Flash Image)?

131,072 tokens, shared between the prompt and the response.

What do I need to try Nano Banana 2 (Gemini 3.1 Flash Image)?

Create an account and add credit; the model is then available both in the browser chat and over the API. There is no contract or minimum spend.

Back to Models

Google

google-nano-banana-2

Nano Banana 2 (Gemini 3.1 Flash Image)

Google's fast, high-quality image generation model.

6/18/2026

131,072 tokens

Per image: $0.078

Try in Chat Get API Key

Specifications

Modalities

Input

text

image

Output

image

Supported Parameters

include_reasoning

max_tokens

reasoning

reasoning_effort

response_format

seed

structured_outputs

temperature

top_p

Max Output Tokens

32,768

Reasoning Configuration

Default: Thinking on (effort: minimal)
Selectable effort levels: high
minimal
Turning thinking off: Possible (reasoning.enabled: false)

How to control thinking, and what it costs

Data policy

Prompt retention: May be retained
Training: Not used for training

Whether a provider trains on prompts is a declared value from our terms with them. Retention is determined from the upstream listing for every host this model can reach. Neither is guessed.

Code Examples

curl https://api.fastmetal.ai/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "model": "google-nano-banana-2",
    "messages": [{"role": "user", "content": "Hello!"}]
  }'

Images generated by Nano Banana 2 (Gemini 3.1 Flash Image)

Generated on FastMetal from the prompts below — no retouching, no cherry-picking.

霧の湖と山の夜明け — generated by Nano Banana 2 (Gemini 3.1 Flash Image) on FastMetal — 夜明けの静かな山上湖。水面に霧が立ちこめ、雪をかぶった峰が鏡のように映り込む写実的な風景写真

和紙テクスチャの浮世絵風の鯉 — generated by Nano Banana 2 (Gemini 3.1 Flash Image) on FastMetal — 和紙の質感を活かした浮世絵風の錦鯉。藍と朱の配色、力強い墨線

Frequently asked questions

How much does the Nano Banana 2 (Gemini 3.1 Flash Image) API cost?: On FastMetal, Nano Banana 2 (Gemini 3.1 Flash Image) is billed per generated image: $0.078 per image on a US-dollar account, before tax — not per token. Usage is drawn from a prepaid balance; there is no subscription or monthly fee.
Can I call Nano Banana 2 (Gemini 3.1 Flash Image) with the OpenAI SDK?: Yes. Point base_url at https://api.fastmetal.ai/v1 and pass "google-nano-banana-2" as the model; existing OpenAI-style code works unchanged, including streaming, tool calls and structured output.
What is the context window of Nano Banana 2 (Gemini 3.1 Flash Image)?: 131,072 tokens, shared between the prompt and the response.
What do I need to try Nano Banana 2 (Gemini 3.1 Flash Image)?: Create an account and add credit; the model is then available both in the browser chat and over the API. There is no contract or minimum spend.