Help with "Validation of media ids failed" for chunked video upload to media/upload



Hi all,

I’ve been trolling the forums to see if there was a clear answer to this, but I had no luck.

We’re using a Node.js backend and the twit library ( to upload some videos to the new chunked /media/upload API.

We are attempting to upload this video as a test:

We’re trying to send it all in one chunk. INIT and APPEND come back with no errors, but as soon as we try FINALIZE, we get the infamous “The validation of media ids failed” 321 error.

A couple of questions we had:

  1. I’m guessing this has something to do with the fact that the video is about 2+ MB and we’re trying to send it over in one chunk?
  2. If this is the case, what is the Twitter recommended maximum size of each chunk?
  3. Is the video above of a format that is suitable for the video API?

Thanks for your help!



  1. That shouldn’t be a problem.
  2. Max chunk size is 5 MB. It is documented at
  3. Your video file is failing due to some audio channels related validations. I will come back with more information. We are also going to improve api error message.


@grales Your video contains 5.1 audio which is not currently supported. We only support Mono (1 channel) and Stereo (2 channels) audio. This constraint is documented at

closed #4

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