Display creatives can use standard images (GIF, JPEG, PNG, or WBMP) as the primary asset.
You can upload high-density image assets up to twice the dimensions of your creative and up to a 10 MB file size. Campaign Manager will scale down the image based on the resolution of the device where it serves. Campaign Manager will only scale the image into sizes with the same aspect ratio as the original asset. For example, if you’re making a 300 x 250 creative, you can upload a high-density image up to 600 x 500. Note that you'll need to use the ins tag for placements with high-density image assets since this tag type properly populates screen density.
Primary HTML5 asset
Display creatives can use HTML5 as the primary asset.
You or your developer can package HTML5 assets and manually upload them to Campaign Manager. You must upload your HTML5 asset as a .zip or .adz containing a maximum of 100 files, and at least one click tag. The maximum file size of the .zip or .adz file is 10 MB. Steps to package HTML5 assets
Campaign Manager also supports responsive HTML assets, which are designed by creative developers to use a flexible layout that can adjust across ad slots and screen sizes. Learn more about building responsive creatives in Google Web Designer
Serving: Campaign Manager will only deliver your backup image if the browser or app cannot handle HTML5.
Polite load file
Upload a polite load image so that you have something to show if there are delays loading your primary HTML5 asset to a browser.
When your creative is delivered, the polite load asset loads first before each impression, followed by your primary HTML5 asset. This way, if the user's browser experiences a delay loading your primary asset, the polite load image will be there until everything else finishes loading. We recommend that your polite load asset matches the first frame of your HTML5 asset so users don’t experience any interruption between the two assets loading.
File type: Add an image file that is under 40 KB. It can be the same asset as your backup image. If you upload multiple image files, choose the one you want in the Polite load file menu.
Dimensions: The polite load image dimensions should match your backup image dimensions.
Add a backup image if your primary asset is HTML5. If you upload multiple image assets, choose them in the Backup image menu in your creative properties.
Dimensions: Should match the HTML5 assets.