The /audio/waveform Robot

We offer a variety of features to reduce audio size while maintaining quality, as well as add effects like loops or watermarks.

The /audio/waveform Robot generates waveform images for your audio files and allows you to change their colors and dimensions.


Name Type Default Description
use (required) String / Array of Strings


Specifies which Step(s) to use as the input to this Robot.

Special Step names

A special Step name is ":original", which provides user uploads handled by Transloadit.

Providing several Steps as input

You can add arrays to use several Steps:
"use": [

Step bundling

Some Robots can gather several Step results for a single invocation. For example, the /file/compress Robot would normally create one Zip file for each file passed to it. If you'd set bundle_steps to true, however, it will create one archive containing all the result files from all Steps you give it. To enable bundling, provide an object like the one below to the use parameter:
  "use": {
    "steps": [
    "bundle_steps": true
This is a crucial parameter for the /video/adaptive Robot, otherwise you'll generate 1 playlist for each viewing quality.
Keep in mind that all input Steps must be present in your Template. If one of them is missing, no result is generated because the Robot waits indefinitely for all input Steps to be finished.

Group by original

Sticking with the /file/compress Robot example, you can set group_by_original to true, in order to create a separate Zip file for each of your uploaded or imported files, instead of creating one archive containing all originals (or one per resulting file). This is a crucial parameter for the /media/playlist Robot.


See a demo for the use parameter here.
format String "image" The format of the result file. Can be "image" or "json".
width Integer 256 The width of the resulting image if the format "image" was selcted.
height Integer 64 The height of the resulting image if the format "image" was selcted.
background_color String "00000000" The background color of the resulting image in the "rrggbbaa" format (red, green, blue, alpha), if the format "image" was selected.
center_color String "000000ff" The color used in the center of the gradient. The format is "rrggbbaa" (red, green, blue, alpha).
outer_color String "000000ff" The color used in the outer parts of the gradient. The format is "rrggbbaa" (red, green, blue, alpha).


Our /audio/waveform Robot can be used in combination with other Robots, to create powerful workflows unique to your use case. Here are a few example scenarios that you can try live on our website:

Blog posts about the /audio/waveform Robot

We wrote the following posts about the /audio/waveform Robot on our blog:

Did you know?

You can easily combine Robots to create powerful workflows, unique to your business.
This is the power of Transloadit.