Banner.mimes

Content MIME types the slot can render, such as image/jpeg or image/gif. OpenRTB 2.0 to 2.2 stated that an absent list allows any type.

Currentstring arrayOptionalSince 2.0

Field facts

Path: imp.banner.mimes, imp.audio.companionad.mimes, imp.video.companionad.mimes
Object: Banner
Type: string array
Requirement: Optional
Added: OpenRTB 2.0
Spec section: 3.2.6

How it is used

List only the types the renderer actually supports. For a companion slot, the list limits the file types the companion creative may use.

Example

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

{
  "id": "req-1",
  "imp": [
    {
      "banner": {
        "mimes": [
          "image/jpeg",
          "image/png",
          "image/gif"
        ]
      }
    }
  ]
}

Common mistakes

Using image/jpg, which appears in older spec examples but is not a registered MIME type. The registered type is image/jpeg.
Still listing application/x-shockwave-flash, which current browsers no longer play.

Version history

Added in OpenRTB 2.0, 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
2.0	array of tring	No	No
2.1	array of string, default All types are allowed	No	No
2.2	array of strings, default All types are allowed	No	No
2.3 to 2.3.1	string array	No	No
2.4	string array	No	No
2.5 to 2.6-202606	string array	No	No