Claude

fal-ai

Inference

Commercial use

FlashVSR+ upscales video by up to 4x with a one-step diffusion model, offering a fast Turbo mode and a higher-quality Base mode. Output reaches about 4K, and the input audio track is preserved by default.

Inference

Commercial use

Playground API Examples

API

fal-ai/flashvsr-plus

fal-aiflashvsr-plus

Playground API Examples

API

fal-ai

Inference

Commercial use

Inference

Commercial use

Playground API Examples

API

1. Calling the API#

Install the client#

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

npm install --save @fal-ai/client

Migrate to @fal-ai/client

The @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.

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

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 { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/flashvsr-plus", {
  input: {
    video_url: "https://storage.googleapis.com/falserverless/example_inputs/birefnet-video-input.mp4"
  },
  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);

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 an environment where you cannot set environment variables, you can configure the API key manually on the client.

import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

Protect your API 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.

3. Queue#

Long-running requests

For long-running requests, such as training jobs or models with slower inference times, it is recommended to check the Queue status and rely on Webhooks instead of blocking while waiting for the result.

Submit a request#

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/flashvsr-plus", {
  input: {
    video_url: "https://storage.googleapis.com/falserverless/example_inputs/birefnet-video-input.mp4"
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

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/flashvsr-plus", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

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/flashvsr-plus", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. 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 { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Auto uploads

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.

5. Schema#

Input#

video_url string* required

The input video to upscale.

upscale_factor float

Spatial upscaling factor. Output is capped at about 4K. Default value: 2

model ModelEnum

turbo: fastest (hybrid sliding attention). base: highest quality. v1: FlashVSR v1.1 weights with the base configuration. Default value: "turbo"

Possible enum values: turbo, base, v1

temporal_compression TemporalCompressionEnum

Input frames per latent frame. Use 2 or 1 for large motion; inference cost rises about 2x or 4x. Default value: "4"

Possible enum values: 1, 2, 4

color_fix boolean

Apply low-frequency wavelet color correction.

preserve_audio boolean

Copy the input audio track into the output. Default value: true

seed integer

The random seed used for the generation process.

video_output_type VideoOutputTypeEnum

Output container/codec. Default value: "X264 (.mp4)"

Possible enum values: X264 (.mp4), VP9 (.webm), PRORES4444 (.mov), GIF (.gif)

video_quality VideoQualityEnum

Output encoding quality. Default value: "high"

Possible enum values: low, medium, high, maximum

video_write_mode VideoWriteModeEnum

Output write mode. Default value: "balanced"

Possible enum values: fast, balanced, small

sync_mode boolean

If True, the media will be returned inline and not stored in history.

enable_safety_checker boolean

Authorized callers may set false to request relaxed screening. Default value: true

{
  "video_url": "https://storage.googleapis.com/falserverless/example_inputs/birefnet-video-input.mp4",
  "upscale_factor": 2,
  "model": "turbo",
  "temporal_compression": 4,
  "preserve_audio": true,
  "video_output_type": "X264 (.mp4)",
  "video_quality": "high",
  "video_write_mode": "balanced",
  "enable_safety_checker": true
}

Output#

video File* required

The upscaled video.

seed integer* required

The random seed used for the generation process.

{
  "video": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019
  }
}

Other types#

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

Related Models

API

1. Calling the API#

Install the client#

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

npm install --save @fal-ai/client

Migrate to @fal-ai/client

The @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.

Setup your API Key#

Set FAL_KEY as an environment variable in your runtime.

export FAL_KEY="YOUR_API_KEY"

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 { fal } from "@fal-ai/client";

const result = await fal.subscribe("fal-ai/flashvsr-plus", {
  input: {
    video_url: "https://storage.googleapis.com/falserverless/example_inputs/birefnet-video-input.mp4"
  },
  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);

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 an environment where you cannot set environment variables, you can configure the API key manually on the client.

import { fal } from "@fal-ai/client";

fal.config({
  credentials: "YOUR_FAL_KEY"
});

Protect your API Key

3. Queue#

Long-running requests

Submit a request#

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/flashvsr-plus", {
  input: {
    video_url: "https://storage.googleapis.com/falserverless/example_inputs/birefnet-video-input.mp4"
  },
  webhookUrl: "https://optional.webhook.url/for/results",
});

Fetch request status#

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/flashvsr-plus", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b",
  logs: true,
});

Get the result#

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/flashvsr-plus", {
  requestId: "764cabcf-b745-4b3e-ae38-1200304cf45b"
});
console.log(result.data);
console.log(result.requestId);

4. 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)#

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 { fal } from "@fal-ai/client";

const file = new File(["Hello, World!"], "hello.txt", { type: "text/plain" });
const url = await fal.storage.upload(file);

Auto uploads

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.

5. Schema#

Input#

video_url string* required

The input video to upscale.

upscale_factor float

Spatial upscaling factor. Output is capped at about 4K. Default value: 2

model ModelEnum

turbo: fastest (hybrid sliding attention). base: highest quality. v1: FlashVSR v1.1 weights with the base configuration. Default value: "turbo"

Possible enum values: turbo, base, v1

temporal_compression TemporalCompressionEnum

Input frames per latent frame. Use 2 or 1 for large motion; inference cost rises about 2x or 4x. Default value: "4"

Possible enum values: 1, 2, 4

color_fix boolean

Apply low-frequency wavelet color correction.

preserve_audio boolean

Copy the input audio track into the output. Default value: true

seed integer

The random seed used for the generation process.

video_output_type VideoOutputTypeEnum

Output container/codec. Default value: "X264 (.mp4)"

Possible enum values: X264 (.mp4), VP9 (.webm), PRORES4444 (.mov), GIF (.gif)

video_quality VideoQualityEnum

Output encoding quality. Default value: "high"

Possible enum values: low, medium, high, maximum

video_write_mode VideoWriteModeEnum

Output write mode. Default value: "balanced"

Possible enum values: fast, balanced, small

sync_mode boolean

If True, the media will be returned inline and not stored in history.

enable_safety_checker boolean

Authorized callers may set false to request relaxed screening. Default value: true

{
  "video_url": "https://storage.googleapis.com/falserverless/example_inputs/birefnet-video-input.mp4",
  "upscale_factor": 2,
  "model": "turbo",
  "temporal_compression": 4,
  "preserve_audio": true,
  "video_output_type": "X264 (.mp4)",
  "video_quality": "high",
  "video_write_mode": "balanced",
  "enable_safety_checker": true
}

Output#

video File* required

The upscaled video.

seed integer* required

The random seed used for the generation process.

{
  "video": {
    "url": "",
    "content_type": "image/png",
    "file_name": "z9RV14K95DvU.png",
    "file_size": 4404019
  }
}

Other types#

File#

url string* required

The URL where the file can be downloaded from.

content_type string

The mime type of the file.

file_name string

The name of the file. It will be auto-generated if not provided.

file_size integer

The size of the file in bytes.

Related Models

FlashVSR+ Video to Video API Docs | fal