What is VAST?

VAST (Video Ad Serving Template) is the IAB standard XML schema for serving video ads. It defines how video ad creatives, tracking pixels, and companion ads are structured so that any ad server can communicate with any video player.

VAST Versions

  • VAST 2.0: Basic linear/non-linear video ads
  • VAST 3.0: Added skippable ads, ad pods, and VPAID support
  • VAST 4.0 / 4.1: Introduced Mezzanine files, ad verification, and UniversalAdId
  • VAST 4.2+: Added ViewableImpression, OMID integration support

Required VAST Elements

Every valid VAST response must include:

  • <VAST> root with version attribute
  • <Ad> container
  • <InLine> or <Wrapper>
  • <AdSystem>, <AdTitle>, <Impression>
  • <Creatives> → <Creative> → <MediaFiles> → <MediaFile>
  • Wrapper responses also require <VASTAdTagURI>