There is a lot of processes and complexity behind the communication of the video ad, video player and third parties. To enable this process in a scalable way, Interactive Advertising Bureau (IAB) set up two important standards – VAST and VPAID.

Common usage of these standards brings essential advantages to all affected subjects:

advantages of VAST and VPAID

  • Reducing expensive technical barriers – you don’t have to spend time and resources on training, developing, and managing custom video ads for ad networks/servers/third-party
  • Saving time – applying unified standards means less time invested in adapting the ad communication to another party
  • Scalability – more volume for publishers to sell and more ad serving impressions for advertisers, which brings in more revenue. It´s a win-win situation for both publishers and advertisers.


VAST stands for the Video Ad Serving Template, a universal specification developed by the IAB for serving video ads.

You can think about VAST as about a universal language used for delivering video ads to digital video players. Structured this way, the ad sever provides consistent instructions to the video player on how to handle an ad – It tells your video player what the ad should do:

  • which ad should the player play
  • how it should show up in the player
  • how long it should display
  • whether the ad is skippable
  • where to find the ad
  • and what the click-through URL is

How it works


  1. A publisher’s video player makes an ad request to its Primary ad server (probably own Publisher´s ad server)
  2. If there is no suitable running campaign at the primary ad server, the advertising party sends a VAST Wrapper response identifying resources from a secondary ad server.
  3. A publisher’s video player makes an ad request to the Secondary Ad Server.
  4. The Secondary Ad Server can respond
    1. with a Wrapper XML pointing to another Secondary Ad Sever (if there is no ad available)
    2. or respond with a VAST-formatted XML document describing the ad to be shown.
  5. Based on the XML response, a set of tracking URIs will be requested by the Video Player for reporting purposes. Both the Primary Ad Server and all Secondary Ad Servers must record impressions.

VAST Ads are fast and responsive, with minimum security issues. Based upon a very simple technology, VAST provides only little amount of information to the advertiser, without an option of an additional banner overlapping the video.

With only VAST tag, no interaction with creative is possible when video is playing (apart from basic functionality like play or full screen). For any further interaction between the ad and the player, the VPAID tag needs to be inserted inside of the VAST wrapper.


Built upon VAST, VPAID stands for The Video Player-Ad Interface Definition. It is a universal specification developed for further interaction between ad units and video players. As a result of high degree of “customization” and interactivity, VPAID can provide more premium experience in terms of video ads.

A VPAID ad is served within the standard VAST wrapper with an interactive file instead of a standard non-interactive video. Upon the VAST tag, it provides us possibility of

  • non-linear ads
  • interaction with the user
  • preloading an ad unit before its rendering
  • tracking each event by user accurately
  • additional information, enhanced viewer analytics for the advertiser
  • customizable options

Thanks to API, whenever any change happens in VPAID, all publisher players will be updated automatically without any need for manual implementation of template.

How it works


  1. The player makes an ad call to the ad server.
  2. The ad server responds with a VPAID-compliant executable ad unit wrapped in a VAST XML
  3. The video player and the ad unit remain in communication as the ad executes and displays to the user. Using VPAID, the video player can get and set properties for the ad unit, and the ad unit can dispatch events to the video player.
  4. The video player and the ad unit can each send impression and activity tracking requests to their respective ad servers.

Before VAST and VPAID, there was no common established protocol for communication with video players in digital video advertising, which made the transfer of information between all the affected parties technically more complicated. In order to serve simple in-stream or rich-media video ads to multiple publishers in an easy and scalable way, VAST and VPAID contributed to even faster development of video advertising. Both advertising protocols became this way a convenient must-have for any advertiser, publisher or third party that has something to do with the communication around the digital video ad.