The /audio/merge Robot

Our /audio/merge robot

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

The /audio/merge Robot overlays several audio files on top of each other.

The /audio/merge Robot's Parameters

Name Type Default Description
preset String "mp3" Performs conversion using pre-configured settings. If you specify your own FFmpeg parameters using the Robot's ffmpeg parameter and you have not specified a preset, then the default "mp3" preset is not applied. This is to prevent you from having to override each of the mp3 preset's values manually. For a list of audio presets, see audio presets.
bitrate Integer Auto Bit rate of the resulting audio file, in bits per second. If not specified will default to the bit rate of the input audio file
sample_rate Integer Auto Sample rate of the resulting audio file, in Hertz. If not specified will default to the sample rate of the input audio file
duration String "longest" Duration of the output file compared to the duration of all merged audio files. Can be "first" (duration of the first input file), "shortest" (duration of the shortest audio file) or "longest" for the duration of the longest input file.

Example use cases featuring the /audio/merge robot

See the robot in action with some live demos and code samples right here on our website:

Audio watermarking

Here you can see a quick example of the Assembly Instructions required to create this encoding pipeline. More information is available in the Live demo

 "steps": {
    "audio_import": {
      "robot": "/http/import",
      "url": ""
    "merge": {
      "robot": "/audio/merge",
      "use": {
        "steps": [
            "name": "audio_import",
            "as": "audio"
            "name": ":original",
            "as": "audio"
      "result": true,
      "preset": "mp3"

Blog posts about the /audio/merge robot

Did you know?

You can easily combine Robots to create powerful workflows, unique to your business.

This is the power of Transloadit.