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gemini-3.1-flash-image-preview

Nano-Banana-2，Google’s latest-generation AI image generation and editing model

2026-02-27

Image Generations

Input:

$0.5/1M Tokensstarting from

Output:

$60/1M Tokensstarting from

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稳定性

Stable

API Overview

Gemini 3.1 Flash Image Preview (Nano Banana 2) is the latest-generation lightweight model for image generation launched by Google. Inheriting the consistently rapid and efficient characteristics of the Flash series, this model is specially optimized for high-throughput and fast-interactive scenarios. It not only delivers high-quality visual generation results but also boasts exceptionally fast response times, making it an ideal choice for applications requiring real-time image generation, interactive visual creation, and large-scale batch production of assets. ───────────────────────────────────────────────────────────────────

Core Capabilities

Ultra-Fast Generation Speed: Designed specifically for real-time responsiveness, this model significantly boosts the throughput of image-generation tasks. While maintaining high-generation quality, it enables users to receive instant feedback.

Efficient and Lightweight: As a member of the Flash family, this model strikes an optimal balance between resource usage and generation efficiency, making it highly suitable for integration into business workflows that frequently call upon image-generation capabilities.

Highly Reliable Visual Output: Although positioned within the efficient Flash series, this model maintains the high standards of the Gemini 3.1 series in terms of color reproduction, lighting and shadow rendering, and instruction matching accuracy, ensuring it can meet diverse visual creation needs.

Seamless Workflow Integration: Supporting API batch processing, this model can be quickly integrated into existing AI-powered automated creation pipelines, providing robust support for large-scale asset production.

API Console

API Analytics

API Reference (8)

API Description	API Endpoint	Request Method	Stability	Parameter Description
gemini-3.1-flash-image-preview (Original Format - Text-to-Image)	https://api.302.ai/google/v1/models/gemini-3.1-flash-image-preview	POST	Stable	View Details
Document Details Nano-Banana-2 model from Google We at 302 have made 2 optimizations to this API: Support returning URL or raw base64 data Support passing image_url for image editing Price: Input 0.5 PTC/1M Tokens Output 60 PTC/1M Tokens Request Parameters Header Parameters Authorizationstring Required Example Value:`Bearer {{YOUR_API_KEY}}` Query Parameters response_formatenum<string> Optional Enum Value: `urlb64_json` Request Body application/json contentsarray[object] Required partsarray[object] Optional textstring Optional generationConfigobject Required responseModalitiesarray[string] Required imageConfigobject Optional aspectRatioenum<string> Optional Enum Value: `1:12.33:23:44.34.55.49:1616:921:9`
gemini-3.1-flash-image-preview (Original Format - Image Editing)	https://api.302.ai/google/v1/models/gemini-3.1-flash-image-preview	POST	Stable	View Details
Document Details Nano-Banana-2 model from Google We at 302 have made 2 optimizations to this API: Support returning URL or raw base64 data Support passing image_url for image editing Price: Input 0.5 PTC/1M Tokens Output 60 PTC/1M Tokens Request Parameters Header Parameters Authorizationstring Required Example Value:`Bearer {{YOUR_API_KEY}}` Query Parameters response_formatenum<string> Optional Enum Value: `urlb64_json` Request Body application/json contentsarray[object] Required partsarray[object] Optional textstring Optional inline_dataobject Optional mime_typestring Required datastring Required
gemini-3.1-flash-image-preview (Chat format)	https://api.302.ai/chat/completions	POST	Stable	View Details
Document Details Google’s latest Gemini image generation model, supporting text-to-image and image-to-image. Simply pass the image URL into image_url. Supported models: gemini-2.5-flash-image gemini-3-pro-image-preview gemini-3.1-flash-image-preview Note: We have adapted the API format to be compatible with OpenAI API format, with response in markdown. This model does not support streaming This model automatically performs contextual image editing based on the conversation history provided Please check pricing at: https://302.ai/price/ Request Parameters Header Parameters Content-Typestring Required Example Value:`application/json` Acceptstring Required Example Value:`application/json` Authorizationstring Optional Example Value:`Bearer {{YOUR_API_KEY}}` Request Body application/json modelstring Required The ID of the model to use. For details on which models are compatible with the Chat API, see the model endpoint compatibility table. messagesarray[object] Required Messages for generating chat completions in chat format. rolestring Optional contentstring Optional temperatureinteger Optional Sampling temperature between 0 and 2. Higher values (e.g., 0.8) make output more random, while lower values (e.g., 0.2) make it more focused and deterministic. We generally recommend altering this or `top_p` but not both. top_pinteger Optional An alternative to temperature sampling called nucleus sampling, where the model considers the results of tokens with top_p probability mass. So 0.1 means only tokens comprising the top 10% probability mass are considered. We generally recommend altering this or `temperature` but not both. ninteger Optional How many chat completion choices to generate for each input message. streamboolean Optional If set, partial message deltas will be sent, like in ChatGPT. Tokens will be sent as data-only server-sent events as they become available, with the stream terminated by a `data: [DONE]` message. See the OpenAI Cookbook for example code. stopstring Optional Up to 4 sequences where the API will stop generating further tokens. max_tokensinteger Optional The maximum number of tokens to generate in the chat completion. The total length of input tokens and generated tokens is limited by the model context length. presence_penaltynumber Optional Number between -2.0 and 2.0. Positive values penalize new tokens based on whether they appear in the text so far, increasing the model likelihood to talk about new topics. See more information about frequency and presence penalties. frequency_penaltynumber Optional Number between -2.0 and 2.0. Positive values penalize new tokens based on their existing frequency in the text so far, decreasing the model likelihood to repeat the same line verbatim. See more information about frequency and presence penalties. logit_biasnull Optional Modify the likelihood of specified tokens appearing in the completion. Accepts a JSON object that maps tokens (specified by their token ID in the tokenizer) to an associated bias value from -100 to 100. Mathematically, the bias is added to the logits generated by the model prior to sampling. The exact effect will vary per model, but values between -1 and 1 should decrease or increase likelihood of selection; values like -100 or 100 should result in a ban or exclusive selection of the relevant token. userstring Optional A unique identifier representing your end-user, which can help OpenAI to monitor and detect abuse. Learn more.
gemini-3.1-flash-image-preview (simultaneous pay-per-use - text-to-image)	https://api.302.ai/ws/api/v3/google/nano-banana-2/text-to-image	POST	Stable	View Details
Document Details Nano-Banana-2 model from Google Price: Resolution 1K/2K 0.08 PTC//request Resolution 4K 0.16 PTC//request Request Parameters Header Parameters Authorizationstring Optional Example Value:`Bearer {{YOUR_API_KEY}}` Request Body application/json promptstring Required Positive prompt for content generation (required). aspect_ratioenum<string> Optional Aspect ratio of the generated media (optional). Enum Value: `1:13:22:33:44:34:55:49:1616:921:9` output_formatenum<string> Optional Output image format (optional). Enum Value: `pngjpeg` enable_sync_modeboolean Optional Enable synchronous mode (optional). If set to true, the function will wait for the result to be generated and uploaded before returning the response. Allows getting results directly in the response, available only via API. enable_base64_outputboolean Optional Enable BASE64 output (optional). If enabled, the output will be encoded as a BASE64 string instead of a URL, available only via API. callbackstring Optional Callback URL (optional). After the generation task is completed, the system will send a result request to this URL. A 200 status code indicates successful receipt. resolutionenum<string> Optional Output image resolution Enum Value: `1k2k4k`
gemini-3.1-flash-image-preview (simultaneous pay-per-use - image editing)	https://api.302.ai/ws/api/v3/google/nano-banana-2/edit	POST	Stable	View Details
Document Details Nano-Banana-2 model from Google Price: Resolution 1K/2K 0.08 PTC//request Resolution 4K 0.16 PTC//request Request Parameters Header Parameters Authorizationstring Optional Example Value:`Bearer {{YOUR_API_KEY}}` Request Body application/json aspect_ratioenum<string> Optional Aspect ratio of the generated media (optional). Enum Value: `1:13:22:33:44:34:55:49:1616:921:9` enable_base64_outputboolean Optional Enable BASE64 output (optional). If enabled, the output will be encoded as a BASE64 string instead of a URL, available only via API. enable_sync_modeboolean Optional Enable synchronous mode (optional). If set to true, the function will wait for the result to be generated and uploaded before returning the response. Allows getting results directly in the response, available only via API. output_formatenum<string> Optional Output image format (optional). Enum Value: `pngjpeg` promptstring Required Positive prompt for content generation (required). resolutionenum<string> Optional Output image resolution Enum Value: `1k2k4k` callbackstring Optional Callback URL (optional). After the generation task is completed, the system will send a result request to this URL. A 200 status code indicates successful receipt. imagesarray[string] Required Image URL
gemini-3.1-flash-image-preview (asynchronous pay-per-use - text-to-image)	https://api.302.ai/ws/api/v3/google/nano-banana-2/text-to-image	POST	Stable	View Details
Document Details Nano-Banana-2 model from Google Async API, requires callingGet Result Price: Resolution 1K/2K 0.08 PTC//request Resolution 4K 0.16 PTC//request Request Parameters Header Parameters Authorizationstring Optional Example Value:`Bearer {{YOUR_API_KEY}}` Request Body application/json promptstring Required Positive prompt for content generation (required). aspect_ratioenum<string> Optional Aspect ratio of the generated media (optional). Enum Value: `1:13:22:33:44:34:55:49:1616:921:9` output_formatenum<string> Optional Output image format (optional). Enum Value: `pngjpeg` enable_sync_modeboolean Optional Enable synchronous mode (optional). If set to true, the function will wait for the result to be generated and uploaded before returning the response. Allows getting results directly in the response, available only via API. enable_base64_outputboolean Optional Enable BASE64 output (optional). If enabled, the output will be encoded as a BASE64 string instead of a URL, available only via API. callbackstring Optional Callback URL (optional). After the generation task is completed, the system will send a result request to this URL. A 200 status code indicates successful receipt. resolutionenum<string> Optional Output image resolution Enum Value: `1k2k4k`
gemini-3.1-flash-image-preview (asynchronous pay-per-use - image editing)	https://api.302.ai/ws/api/v3/google/nano-banana-2/edit	POST	Stable	View Details
Document Details Nano-Banana-2 model from Google Async API, requires callingGet Result Price: Resolution 1K/2K 0.08 PTC//request Resolution 4K 0.16 PTC//request Request Parameters Header Parameters Authorizationstring Optional Example Value:`Bearer {{YOUR_API_KEY}}` Request Body application/json aspect_ratioenum<string> Optional Aspect ratio of the generated media (optional). Enum Value: `1:13:22:33:44:34:55:49:1616:921:9` enable_base64_outputboolean Optional Enable BASE64 output (optional). If enabled, the output will be encoded as a BASE64 string instead of a URL, available only via API. enable_sync_modeboolean Optional Enable synchronous mode (optional). If set to true, the function will wait for the result to be generated and uploaded before returning the response. Allows getting results directly in the response, available only via API. output_formatenum<string> Optional Output image format (optional). Enum Value: `pngjpeg` promptstring Required Positive prompt for content generation (required). resolutionenum<string> Optional Output image resolution Enum Value: `1k2k4k` callbackstring Optional Callback URL (optional). After the generation task is completed, the system will send a result request to this URL. A 200 status code indicates successful receipt. imagesarray[string] Required Image URL
gemini-3.1-flash-image-preview (asynchronous result retrieval)	https://api.302.ai/ws/api/v3/predictions/{requestId}/result	GET	Stable	View Details
Document Details Get the requestId from the generation task request, then fill it into the API to retrieve results Price: Free Request Parameters Path Parameters requestIdstring Required Header Parameters Authorizationstring Required Example Value:`Bearer {{YOUR_API_KEY}}`

API Pricing

$￥円 ₽

Model	Description	Official Price	302.AI Price

gemini-3.1-flash-image-preview	gemini-3.1-flash-image-preview (Official Format - Text-to-Image)	Input$0.5 / 1M Tokens Output$60 / 1M Tokens	Input$0.5/ 1M Tokens Output$60/ 1M Tokens Original Price
gemini-3.1-flash-image-preview	gemini-3.1-flash-image-preview (Official Format - Image Editing)	Input$0.5 / 1M Tokens Output$60 / 1M Tokens	Input$0.5/ 1M Tokens Output$60/ 1M Tokens Original Price
gemini-3.1-flash-image-preview	gemini-3-pro-image-preview (Chat format)	Input$0.5 / 1M Tokens Output$60 / 1M Tokens	Input$0.5/ 1M Tokens Output$60/ 1M Tokens Original Price
gemini-3.1-flash-image-preview	gemini-3.1-flash-image-preview（1K/2K）	$0.08 / call	$0.08/Call
gemini-3.1-flash-image-preview	gemini-3.1-flash-image-preview（4K）	$0.16 / call	$0.16/Call
gemini-3.1-flash-image-preview	gemini-3.1-flash-image-preview (asynchronous result retrieval)	0 / call	Free

gemini-3.1-flash-image-preview

API Overview

Core Capabilities

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API Reference (8)

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API Pricing