Expandables and Rich Media
AppNexus is adding expandable rich media support on all supply from platform networks and AppNexus-enabled exchanges, including the Microsoft Advertising Exchange.
We have assembled an AppNexus expandable specification based on the specs of our many supply sources. The goal is to have an "upload once, run everywhere" spec.
Creatives that do not meet this spec will still be allowed to run on the platform, but we expect publisher acceptance to be much lower.
Allowed sizes and maximum expanded size
Maximum Expanded Size
120 x 600
240 x 600
160 x 600
320 x 600
300 x 250
500 x 300
468 x 60
468 x 210
728 x 90
728 x 300
234 x 60
300 x 250
120 x 60
120 x 240
180 x 150
300 x 300
300 x 600
560 x 600
For mobile interstitials, register creatives as standard banner and target interstitial sizes in the bid request.
Expandables are implemented through a broader "media type" system in AppNexus. This system allows us to align placements and creatives so that all technical requirements are met for proper rendering.
Media types and subtypes are in a two-tiered hierarchy:
Image and Text
ReactX Left/ Right
DEPRECATED 15-second VAST
DEPRECATED 30-second VAST
DEPRECATED Other VAST
Placements may accept any combination of media types or subtypes. If they accept a media type, they accept all subtypes under the media type.
Creatives have one template, which specifies the format of the creative and the expandable vendor in use. A creative may serve only on placements that accept the creative template's media subtype or its parent media type.
There are two touch points for our expandable integration: a change to the RTB protocol, and a change to creative upload.
There will be two new fields in the bid request to indicate the availability of expandables on an impression.
Array of media type ids
This field is optional. If it appears, creatives of the specified media types may serve on this impression.
Array of media subtype ids
This field is optional. If it appears, creatives of the specified media subtypes may serve on this impression.
Array of media subtype in string format
This field is optional. If it appears, it will list the allowed media in string format.
These fields will be on each "tag" object in the bid request:
To determine if your expandable creative will serve:
- First, check if "allowed_media_types" contains the "Expandable" Media Type.
- If "Expandable" is not in "allowed_media_types", check if the media_subtype id is allowed in "allowed_media_subtypes".
When expandable creatives are uploaded to the Creative Service, you will need to denote the expandable ad server being used.
JSON object with the ID of the associated template.
To denote an expandable, select the template that corresponds to the expandable vendor in use, and the creative format used by your bidder. If the vendor in use is not listed, use "Other Expandable".
This field is required on expandable creatives.
- You are not required to set the template ID on standard creatives (non-expandable). Continue uploading those creatives as you did before.
- Traffic Skin creatives as a standard banner. We recommend using 1800 X 1000 dimensions.
The following table lists the available templates and their associated IDs.
Expandables for bidders will only work with the templates listed below. Please do not use custom templates for expandables.
Creatives that are of the media type Expandable will not serve on external mobile supply. If it's a mobile expandable creative, use a template with the banner media type and non-iframe html format, and set up
alternative_landing_page_url in your creative.
Expandable Media Subtype
Please contact your account AppNexus representative with any questions about expandable or video integration.