Audio.mimes

The audio file MIME types the player can play, such as audio/mpeg or audio/mp4. Required since the object arrived in 2.4, and the only required field on it.

Currentstring arrayRequiredSince 2.4

Field facts

Path: imp.audio.mimes
Object: Audio
Type: string array
Requirement: Required
Added: OpenRTB 2.4
Spec section: 3.2.8

How it is used

List what the player, or the stitcher in a server-side setup, can decode. MP3 files are usually labeled audio/mpeg, and AAC files audio/aac or audio/mp4. Buyers match the list against the MediaFile types in their VAST creatives.

Example

Where the field sits in a payload, with everything else left out:

{
  "id": "req-1",
  "imp": [
    {
      "audio": {
        "mimes": [
          "audio/mpeg",
          "audio/mp4"
        ]
      }
    }
  ]
}

Common mistakes

Sending an empty array, which offers no playable format.
Copying video MIME types from a video template, so no audio creative matches.

Version history

Added in OpenRTB 2.4, and present in the latest snapshot. The table shows how each version's spec text types the field.

Versions	Type in the spec	Required	Deprecated
2.4	string array	Yes	No
2.5 to 2.6-202606	string array	Yes	No

Related fields

Other Audio fields

For a walkthrough of the whole object, read Audio object guide.