VPAID

VPAID, or Video Player Ad-Serving Interface Definition, is a standard from the IAB Tech Lab that defines a bidirectional API for interactive video ad units to communicate with a video player. Its purpose is to standardize how ad creatives control playback, report metrics, and respond to player events, enabling richer in-stream ad experiences while preserving predictable behavior for the player.

How it works: A VAST response may reference a VPAID creative. The video player loads the VPAID component (traditionally in Flash or HTML5) and calls the creative’s API, including initAd, startAd, stopAd, pauseAd, resumeAd, resizeAd, and setAdVolume or getAdVolume. The creative can emit events such as AdImpression, AdVideoStart, AdVideoComplete, AdClickThrough, and AdError to the host player. This interaction allows interactive overlays, custom controls, and other immersive formats within the video unit.

Versions and scope: VPAID has undergone several revisions, with 1.x and 2.x as major lines. VPAID 2.x emphasizes cross-platform compatibility and improved security, and HTML5-based VPAID is commonly used today as Flash support declines. The standard is designed to work with VAST ad playback, providing a contract between the ad creative and the player.

Adoption and considerations: VPAID is widely supported by many video players and ad servers, but compatibility can vary across environments. Some publishers and platforms restrict or disable VPAID due to security, performance, or complexity concerns, favoring VAST-only or non-VPAID alternatives. When used, VPAID enables interactive ad formats such as overlays, quizzes, and other user engagements within in-stream video.

See also: VAST, IAB Tech Lab, HTML5 advertising.