We are a Swiss Army knife for your files
Transloadit is a service for companies with developers. We handle their file uploads and media processing. This means that they can save on development time and the heavy machinery that is required to handle big volumes in an automated way.
We pioneered with this concept in 2009 and have made our customers happy ever since. We are still actively improving our service in 2026, as well as our open source projects uppy.io and tus.io, which are changing how the world does file uploading.
Encode a fade effect between concatenated video files.
🤖/video/concat enables you to concatenate together all your video files quickly and easily whilst encoding a fade effect between each clip.
If you were looking for a way to add some extra flair to your concatenated videos you are in luck.
With this demo, we are going to show how adding both the video_fade_seconds and
audio_fade_seconds parameters can make all the difference. As well, we are going to look into how
we can overcome the parameters shortcoming of not adding a fade effect at the beginning of your
videos using the ffmpeg parameter.
To make sure we have everything all set up as needed for our concatenation to take place, we first
need to resize both of our video clips. We do this by passing both our imported videos to
🤖/video/encode making sure we set the same dimensions and preset
value.
Now we have both our files prepared we can pass them to
🤖/video/concat. Within our use parameter we set up both the name
value of our previously resized step, along with an as value. When concatenating videos
the order they are set in is specified by how we set up by our as value, so for example
as: "video_1" would come before as: "video_2".
To add our fancy fade effect we set up both the video_fade_seconds and audio_fade_seconds
parameters with values to specify how long we want these transitions to last between each video
file. These parameters allow you to seamlessly create both an audio and video fade effect between
your video files. This even allows for millisecond values to be represented by using decimal values.
So if you wanted the fade effect to last 750 milliseconds, you would select 0.75.
With our fade effects in place, why don't we add a video fade at the beginning of our video? Because
🤖/video/concat works by using
FFMpeg, if we try add any additional vf parameter
values, this will result in a error. So to bypass this, we need to pass our concatenate step to
🤖/video/encode. We have already encoded our videos preset value in
our previous step, so no need to do that again. Simply add a preset parameter, and set its value
to empty so the Robot can run as intended.
Using our ffmpeg parameter, we set up a vf parameter and set its value to
fade=type=in:duration=1. This creates a video fade-in effect at the start of our final file.
Now with everything set up, we are good to run and see the final result. Happy Encoding!
Step 1:
Handle uploads
We can handle uploads of your users directly.Learn more
":original": {
"robot": "/upload/handle"
}Step 2:
Import files from web servers
We are happy to import from whatever storage solution suits you best.Learn more
"preroll_imported": {
"robot": "/http/import",
"result": true,
"url": "https://demos.transloadit.com/inputs/waves10.mp4"
}Step 3:
Transcode, resize, or watermark videos
We offer a variety of video encoding features like optimizing for different devices, merging, injecting ads, changing audio tracks, or adding company logos.Learn more
"preroll_resized": {
"use": "preroll_imported",
"robot": "/video/encode",
"result": true,
"background": "#00000000",
"ffmpeg_stack": "v7",
"height": 270,
"preset": "ipad-high",
"resize_strategy": "pad",
"turbo": false,
"width": 480
}Step 4:
Transcode, resize, or watermark videos
We offer a variety of video encoding features like optimizing for different devices, merging, injecting ads, changing audio tracks, or adding company logos.Learn more
"original_resized": {
"use": ":original",
"robot": "/video/encode",
"result": true,
"background": "#00000000",
"ffmpeg_stack": "v7",
"height": 270,
"preset": "ipad-high",
"resize_strategy": "pad",
"turbo": false,
"width": 480
}Step 5:
Concatenate videos
We offer a variety of video encoding features like optimizing for different devices, merging, injecting ads, changing audio tracks, or adding company logos.Learn more
"concatenated": {
"use": {
"steps": [
{
"name": "original_resized",
"as": "video_1"
},
{
"name": "preroll_resized",
"as": "video_2"
}
]
},
"robot": "/video/concat",
"result": true,
"audio_fade_seconds": 1,
"ffmpeg_stack": "v7",
"preset": "ipad-high",
"video_fade_seconds": 1
}Step 6:
Transcode, resize, or watermark videos
We offer a variety of video encoding features like optimizing for different devices, merging, injecting ads, changing audio tracks, or adding company logos.Learn more
"encode": {
"use": "concatenated",
"robot": "/video/encode",
"ffmpeg": {
"vf": "fade=type=in:duration=1"
},
"ffmpeg_stack": "v7",
"preset": "empty",
"turbo": false
}Step 7:
Export files to Amazon S3
We export to the storage platform of your choice.Learn more
:originalpreroll_importedpreroll_resizedoriginal_resizedconcatenatedencode"exported": {
"use": [
"preroll_imported",
"preroll_resized",
"original_resized",
"concatenated",
"encode",
":original"
],
"robot": "/s3/store",
"credentials": "demo_s3_credentials",
"url_prefix": "https://demos.transloadit.com/"
}Live Demo. See for yourself
Loading Uppy demo…
This live demo is powered by 
Uppy, our open source file uploader that you can also use without Transloadit, and 
tus, our open protocol for resumable file uploads that is making uploading more reliable across the world.
Build this in your own language
<!-- This pulls Uppy from our CDN -->
<!-- For smaller self-hosted bundles, install Uppy and plugins manually: -->
<!-- npm i --save @uppy/core @uppy/dashboard @uppy/remote-sources @uppy/transloadit ... -->
<link
href="https://releases.transloadit.com/uppy/v3.10.0/uppy.min.css"
rel="stylesheet"
/>
<button id="browse">Select Files</button>
<script type="module">
import {
Uppy,
Dashboard,
ImageEditor,
RemoteSources,
Transloadit,
} from 'https://releases.transloadit.com/uppy/v3.10.0/uppy.min.mjs'
const uppy = new Uppy()
.use(Transloadit, {
waitForEncoding: true,
alwaysRunAssembly: true,
assemblyOptions: {
params: {
// It's often better store encoding instructions in your account
// and use a `template_id` instead of adding these steps inline
steps: {
':original': {
robot: '/upload/handle',
},
preroll_imported: {
robot: '/http/import',
result: true,
url: 'https://demos.transloadit.com/inputs/waves10.mp4',
},
preroll_resized: {
use: 'preroll_imported',
robot: '/video/encode',
result: true,
background: '#00000000',
ffmpeg_stack: 'v7',
height: 270,
preset: 'ipad-high',
resize_strategy: 'pad',
turbo: false,
width: 480,
},
original_resized: {
use: ':original',
robot: '/video/encode',
result: true,
background: '#00000000',
ffmpeg_stack: 'v7',
height: 270,
preset: 'ipad-high',
resize_strategy: 'pad',
turbo: false,
width: 480,
},
concatenated: {
use: {
steps: [
{
name: 'original_resized',
as: 'video_1',
},
, {
name: 'preroll_resized',
as: 'video_2',
},
],
},
robot: '/video/concat',
result: true,
audio_fade_seconds: 1,
ffmpeg_stack: 'v7',
preset: 'ipad-high',
video_fade_seconds: 1,
},
encode: {
use: 'concatenated',
robot: '/video/encode',
ffmpeg: {
vf: 'fade=type=in:duration=1',
},
ffmpeg_stack: 'v7',
preset: 'empty',
turbo: false,
},
exported: {
use: ['preroll_imported', 'preroll_resized', 'original_resized', 'concatenated', 'encode', ':original'],
robot: '/s3/store',
credentials: 'demo_s3_credentials',
url_prefix: 'https://demos.transloadit.com/',
},
},
},
},
})
.use(Dashboard, { trigger: '#browse' })
.use(ImageEditor, { target: Dashboard })
.use(RemoteSources, {
companionUrl: 'https://api2.transloadit.com/companion',
})
.on('complete', ({ transloadit }) => {
// Due to `waitForEncoding:true` this is fired after encoding is done.
// Alternatively, set `waitForEncoding` to `false` and provide a `notify_url`
console.log(transloadit) // Array of Assembly Statuses
for (const assembly of transloadit) {
console.log(assembly.results) // Array of all encoding results
}
})
.on('error', (error) => {
console.error(error)
})
</script>
So many ways to integrate
Transloadit is a service for companies with developers. And there are many ways developers can put Transloadit to good use inside your company to automate media processing.
Bulk imports
Add one of our import Robots to acquire and transcode massive media libraries.
Handling uploads
We are the experts at reliably handling uploads. We wrote the protocol for it.
Front-end integration
We integrate with web browsers via our next-gen file uploader Uppy and SDKs for Android and iOS.
Back-end integration
Send us batch jobs in any server language using one of our SDKs or directly interfacing with our REST API.
Pingbacks
Configure a notify_url to let your server receive transcoding results JSON in the transloadit POST field.
On-demand
Use our Smart CDN to adapt files on-demand and stream them directly to your users.
Video encoding
Document processing