To discuss and provide feedback on our products, join the official Ad Manager Discord channel in the Google Advertising and Measurement Community server.

Preload media

AI-generated Key Takeaways

The IMA SDK supports preloading video ad assets to provide a more seamless transition between ads and content.
You can enable preloading by setting AdsRenderingSettings.enablePreloading to true within the ADS_MANAGER_LOADED event.
Preloading changes the timing of when different ad types are loaded compared to not using preloading.
Media preloading is subject to limitations, including not being available on mobile web on iOS or HTML5 on connected smart TVs, and how VPAID and VMAP ads are handled.
Media preloading loads as much of the creative as the browser allows and is not intended for offline ad serving.

Select platform: HTML5 Android

The IMA SDK supports preloading video ad assets. You can enable this feature in your SDK integration to provide a more seamless transition between ads and content. This guide goes over the technical details of implementing media preload with the IMA SDK.

Enable preloading

To enable preloading, set AdsRenderingSettings.enablePreloading to true. This must be done as a result of the ADS_MANAGER_LOADED event:

function onAdsManagerLoaded(adsManagerLoadedEvent) {
  var adsRenderingSettings = new google.ima.AdsRenderingSettings();
  adsRenderingSettings.enablePreloading = true;
  ...
  var adsManager = adsManagerLoadedEvent.getAdsManager(
      videoContent, adsRenderingSettings);
}

Timing

The following table summarizes the changes in ad-load timing when preloading is enabled:

Event	With Preload	Without Preload
Ad VAST requested	`AdsLoader.requestAds()`	`AdsLoader.requestAds()`
Pre-roll loaded (single ad)	`AdsManager.init()`	`AdsManager.start()`
Pre-roll loaded (VMAP/Ad rules)	`AdsManager.init()`	`AdsManager.init()`
Mid-roll or post-roll loaded	For the 1st ad in an ad break, 8 seconds before ad start time. For consecutive ads, when the previous ad starts playing.	At ad start time.

Limitations

Preloading is subject to the following limitations:

Media preloading is not available on the mobile web on iOS devices or when using the HTML5 IMA SDK on connected smart TVs.
VPAID is preloaded, but none of the ad's dependencies—including media played by that ad—are loaded until the ad is executed.
Autoplay must be enabled to preload VMAP ads. Ensure that settings.isAutoPlayAdBreaks() is set to true, which is the default value.
Post-rolls are preloaded following the last mid-roll, or 8 seconds before the end of content if AdsRequest.contentDuration is used to set the duration.

FAQ

Does media preloading load the full creative?: No, the creative is usually not fully loaded when ad playback begins. Preloading is intended for improving the user experience by minimizing the time it takes for the ad to load. It is not intended to support offline ad serving. The IMA SDK loads as much of the media as the browser allows, limited by the user's internet connection and the size of the creative.
Does media preloading need to be enabled for the ad's VAST as well as media?: No, the SDK always preloads the ad's VAST, regardless of this preload setting.