Trouble-shooting HTML5 creatives

In the interst of keeping the loading times of our sites quick and offer a positive user experience to our customers, we impose weight limits for creatives.

HTML5 creatives can get pretty heavy pretty quickly, especially when they contain video components. It is important for the Carsales team and for client to know that HTML5 creatives can be programmed so that the browser loads an initial set of files and code (the minimum that is needed to display the creative = initial load) and the rest of the creative, with potentially much heavier files, is loaded when the parent site (Carsales, Bikesales...) has finished loading. This is referred to as polite loading. It allows for creativity and much heavier files without impacting the user experience in a negative way by delaying site loads.

At Carsales, we have weight limits for initial load and subload. For details please refer to our creative specs but we generally allow 100 K for initial load and 1 MB for polite load (sub load)

In the past, is was quite tricky to check even the total weight of a HTML5 ad, let alone break it down into initial and subsequent load.

However, the IAB provide a HTML 5 Validator that makes this task easy-peasy:

  1.  Register here:
  2. Upload a zip file in case the creative is hosted in SAS. Copy and paste your tag into the console if you receive an 3rd party tag and click <Upload and Test> (Project Name and User agent are optional):
  3. The HTML5 Validator then analyses your ad and returns the following: 

Additionally, the validator checks whether the creative contains a clickTag (see the last tab <File Breakdown>):









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