The /video/concat Robot

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

The /video/concat Robot concatenates several videos together.


Name Type Default Description
preset String "flash" 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 "flash" preset is not applied. This is to prevent you from having to override each of the flash preset's values manually. For a list of video presets, see video presets.

Example use cases

Our /video/concat Robot can be used in combination with other Robots, to create powerful workflows unique to your use case.
Here are a few example scenarios, and the required the Assembly Instructions to implement them.
You can also try demos of these examples right here, live on our website.

Concatenate two video files

  "steps": {
    "imported_preroll": {
      "robot": "/http/import",
      "url": ""
    "concat": {
      "use": {
        "steps": [
            "name": "imported_preroll",
            "as": "video_1"
            "name": ":original",
            "fields": "test-file",
            "as": "video_2"
      "robot": "/video/concat",
      "result": true,
      "ffmpeg_stack": "v2.2.3",
      "preset": "ipad"

Related blog posts

Over the years we wrote the following posts about Our /video/concat 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.