Clarity Upscaler

Commercial use

1. Calling the API#

Install the client#

The client provides a convenient way to interact with the model API.

npm install --save @fal-ai/serverless-client

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.


Submit a request#

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 * as fal from "@fal-ai/serverless-client";

const result = await fal.subscribe("fal-ai/clarity-upscaler", {
  input: {
    image_url: ""
  logs: true,
  onQueueUpdate: (update) => {
    if (update.status === "IN_PROGRESS") { => log.message).forEach(console.log);

2. Authentication#

The API uses an API Key for authentication. It is recommended you set the FAL_KEY environment variable in your runtime when possible.

API Key#

In case your app is running in an environment where you cannot set environment variables, you can set the API Key manually as a client configuration.
import * as fal from "@fal-ai/serverless-client";

  credentials: "YOUR_FAL_KEY"

3. Files#

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.

Data URI (base64)#

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.

Hosted files (URL)#

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.

Uploading files#

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 * as fal from "@fal-ai/serverless-client";

// Upload a file (you can get a file reference from an input element or a drag-and-drop event)
const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await;

// Use the URL in your request
const result = await fal.subscribe("fal-ai/clarity-upscaler", { image_url: url });

Read more about file handling in our file upload guide.

4. Schema#



The URL of the image to upscale.


The prompt to use for generating the image. Be as descriptive as possible for best results. Default value: "masterpiece, best quality, highres"


The upscale factor Default value: 2


The negative prompt to use. Use it to address details that you don't want in the image. Default value: "(worst quality, low quality, normal quality:2)"


The creativity of the model. The higher the creativity, the more the model will deviate from the prompt. Refers to the denoise strength of the sampling. Default value: 0.35


The resemblance of the upscaled image to the original image. The higher the resemblance, the more the model will try to keep the original image. Refers to the strength of the ControlNet. Default value: 0.6


The CFG (Classifier Free Guidance) scale is a measure of how close you want the model to stick to your prompt when looking for a related image to show you. Default value: 4


The number of inference steps to perform. Default value: 18


The same seed and the same prompt given to the same version of Stable Diffusion will output the same image every time.


If set to false, the safety checker will be disabled. Default value: true

  "image_url": "",
  "prompt": "masterpiece, best quality, highres",
  "upscale_factor": 2,
  "negative_prompt": "(worst quality, low quality, normal quality:2)",
  "creativity": 0.35,
  "resemblance": 0.6,
  "guidance_scale": 4,
  "num_inference_steps": 18,
  "enable_safety_checker": true



The URL of the generated image.


The seed used to generate the image.


The timings of the different steps in the workflow.

  "image": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019,
    "width": 1024,
    "height": 1024