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Resize an image to one or more exact target dimensions. Smart Resize
uses nano-banana-pro internally: for each requested <width>x<height>
the endpoint
picks the smallest nano-banana-pro preset that fully covers the
target, regenerates the image with an adaptive prompt, and then
center-crops it to the exact requested dimensions so the output is
pixel-perfect.
The client provides a convenient way to interact with the model API.
npm install --save @fal-ai/clientThe @fal-ai/serverless-client package has been deprecated in favor of @fal-ai/client. Install the new package and update your imports — see client setup.
Set FAL_KEY as an environment variable in your runtime.
export FAL_KEY="YOUR_API_KEY"The client API handles the API submit protocol. It will handle the request status updates and return the result when the request is completed.
import { fal } from "@fal-ai/client";
const result = await fal.subscribe("fal-ai/smart-resize", {
input: {
image_url: "https://storage.googleapis.com/falserverless/example_inputs/nano-banana-edit-input.png",
target_sizes: ["1024x1024", "1920x1080", "768x1344"]
},
logs: true,
onQueueUpdate: (update) => {
if (update.status === "IN_PROGRESS") {
update.logs.map((log) => log.message).forEach(console.log);
}
},
});
console.log(result.data);
console.log(result.requestId);The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.
import { fal } from "@fal-ai/client";
fal.config({
credentials: "YOUR_FAL_KEY"
});When running code on the client-side (e.g. in a browser, mobile app or GUI applications), make sure to not expose your FAL_KEY. Instead, use a server-side proxy to make requests to the API. For more information, check out our server-side integration guide.
The client API provides a convenient way to submit requests to the model.
import { fal } from "@fal-ai/client";
const { request_id } = await fal.queue.submit("fal-ai/smart-resize", {
input: {
image_url: "https://storage.googleapis.com/falserverless/example_inputs/nano-banana-edit-input.png",
target_sizes: ["1024x1024", "1920x1080", "768x1344"]
},
webhookUrl: "https://optional.webhook.url/for/results",
});You can fetch the status of a request to check if it is completed or still in progress.
import { fal } from "@fal-ai/client";
const status = await fal.queue.status("fal-ai/smart-resize", {
requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
logs: true,
});Once the request is completed, you can fetch the result. See the Output Schema for the expected result format.
import { fal } from "@fal-ai/client";
const result = await fal.queue.result("fal-ai/smart-resize", {
requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);Some attributes in the API accept file URLs as input. Whenever that's the case you can pass your own URL or a Base64 data URI.
You can pass a Base64 data URI as a file input. The API will handle the file decoding for you. Keep in mind that for large files, this alternative although convenient can impact the request performance.
You can also pass your own URLs as long as they are publicly accessible. Be aware that some hosts might block cross-site requests, rate-limit, or consider the request as a bot.
We provide a convenient file storage that allows you to upload files and use them in your requests. You can upload files using the client API and use the returned URL in your requests.
import { fal } from "@fal-ai/client";
const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);The client will auto-upload the file for you if you pass a binary object (e.g. File, Data).
Read more about file handling in our file upload guide.
image_url string* requiredThe URL of the source image to resize.
The list of target dimensions to generate, each written as <width>x<height> (e.g. "1920x1080"). One output image is produced per target size (multiplied by num_images_per_size). The endpoint internally picks the smallest nano-banana-pro preset that fully covers each target so the final image is a pixel-perfect match with no upscaling.
prompt stringOptional extra instruction that is forwarded to nano-banana-pro alongside the auto-generated resize prompt. Leave empty to let the model preserve the original image content as closely as possible. Default value: ""
num_images_per_size integerThe number of nano-banana-pro variants to produce for each target size. The response images list will contain len(target_sizes) * num_images_per_size images in total. Default value: 1
resolution ResolutionEnumHint for the minimum resolution tier to use internally. The smart-resize algorithm may pick a higher tier automatically when the requested target size is too large for this tier. This field does not affect the final output dimensions — those come from target_sizes. Default value: "1K"
Possible enum values: 1K, 2K, 4K
output_format OutputFormatEnumThe output image format. Default value: "png"
Possible enum values: jpeg, png, webp
safety_tolerance SafetyToleranceEnumThe safety tolerance level applied to the inner nano-banana-pro /edit calls. Higher numbers loosen safety filtering. Default value: "4"
Possible enum values: 1, 2, 3, 4, 5, 6
seed integerOptional random seed forwarded to the inner nano-banana-pro /edit calls for reproducibility. The same seed is used for every target size when set.
sync_mode booleanWhen True, the response contains data URIs in place of CDN URLs so the client can decode the images without an extra HTTP request. Adds latency for large outputs.
{
"image_url": "https://storage.googleapis.com/falserverless/example_inputs/nano-banana-edit-input.png",
"target_sizes": [
"1024x1024",
"1920x1080",
"768x1344"
],
"prompt": "",
"num_images_per_size": 1,
"resolution": "1K",
"output_format": "png",
"safety_tolerance": "4"
}All generated images, flattened across every target size. Order matches the order of results below: the first num_images_per_size entries correspond to target_sizes[0] and so on.
description string* requiredThe description of the generated images.
Per-target-size breakdown with the requested width/height and the nano-banana-pro (aspect_ratio, resolution) preset that was used internally.
{
"images": [
{
"content_type": "image/png",
"file_name": "nano-banana-pro-edit-output.png",
"url": "https://storage.googleapis.com/falserverless/example_outputs/nano-banana-pro-edit-output.png"
}
],
"description": "",
"results": [
{
"images": [
{
"url": "",
"content_type": "image/png",
"file_name": "z9RV14K95DvU.png",
"file_size": 4404019
}
],
"description": "",
"aspect_ratio": "",
"resolution": ""
}
]
}The generated images.
description string* requiredThe description of the generated images.
width integer* requiredThe requested target width in pixels.
height integer* requiredThe requested target height in pixels.
aspect_ratio string* requiredThe nano-banana-pro aspect ratio that was used internally for this target size.
resolution string* requiredThe nano-banana-pro resolution tier that was used internally for this target size.
url string* requiredThe URL where the file can be downloaded from.
content_type stringThe mime type of the file.
file_name stringThe name of the file. It will be auto-generated if not provided.
file_size integerThe size of the file in bytes.
width integerThe width of the image
height integerThe height of the image