What is VAST & VPAID and Why is it Important for Video Advertising

  • Post category:Video Advertising
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  • Post last modified:June 27, 2024

Studies have shown that video ads are the most effective medium of advertising when compared to other forms. Check out these stats:

We’ve all heard of VAST ad and VPAID, and how important adopting these standards are.

What is a VAST ad or VAST tag? What is the difference between VAST and VPAID? And how it affects your ad operations?

If you want to run video ads, it is important for you to understand the basics.

It is palpable that video is an effective mobile advertising medium. For the past few years, video consumption is ascending quickly. Also, many advertisers and marketers have joined the bandwagon, with more expecting to adopt video marketing soon.

And on top of normal video ads, it’s reported that interactive video ads drive more brand awareness & engagement.

Briefly, interactive video ads compared to non-interactive video ads:

  • Have 4 times higher interaction rate compared to non-interactive video ads
  • 4% higher brand awareness
  • 5% lift in users purchase intent
  • 2% more message association

If you want to optimize your video ads reach and view engagement, standard-based advertising should be part of your ad planning.

So what exactly are these VAST & VPAID and how does it work for interactive video advertising?

What is VAST Ad, VPAID and how it works

The world of digital advertising is an alphabet soup of ad tech jargon.

Thanks to the Interactive Advertising Bureau (IAB), there is clear guidelines and framework you can get your rich media vendor to follow through.

Let’s get down to basics.

VAST or “Video Ad Serving Template”

  • A specification developed by the IAB for serving video ads.
  • Provides a generic framework for embedding in-stream video ads.
  • Designed to facilitate and standardize the communication between video players and video ad server

Video Players

  • Players that are embedded on publisher’s website or in mobile apps, and used to display ads and videos.

VAST / Video Ad Server

  • Advertising server that is used by advertisers to host and serve their video ads, and count their impressions.
  • Based on ad requests coming from VAST tag, the video ad server will return the creatives criteria like what to serve, how the video is to be played, and what metrics to be tracked.

Read: How does video ad serving work


  • A set of standardized code (based on VAST guidelines) that is placed on publisher’s site or in-app that communicates with the ad server.
  • It tells the server what type of ad to be displayed based on targeting criteria.
  • Each ad space will need a new ad tag.

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Here’s a diagram to further illustrate the above.


Think of IAB VAST as scripts that give consistent instructions to the viewers’ video players on how to handle an ad. It tells the player

  • which ad to play,
  • how the ad should show up,
  • how long it should last, and
  • whether the viewers can skip it
  • where to find the ad (the ad server)
  • what the click-through URL should be
  • and more

VAST tag comes in many versions. Despite the release of VAST 3.0, while VAST 4.0 is under drafting and yet to be officially released by IAB, most publishers are still on VAST 2.0.  However, VAST tag is backwards compatible, so you don’t have to worry about compatibility issues.

VAST 3.0 introduces advanced specifications for both ad serving and video playback in a video player. It considers relevant cross-platform scenarios like mobile, connected TVs, and HTML5 environments. The definition takes a closer look at media file attributes and the containers required for media playback, introduce skippable ads, and improve HTML5 support.

One critical update on VAST 4.0 is that it addresses viewable impressions, where it standardizes the viewability tracking.

Why is VAST ad important? It’s important because it enables video players and ad servers to speak the same language.

With regulation, advertisers don’t have to worry about their video ads not able to run on many players. And publishers don’t have to worry about limited inventories.

In other words, it means more volume for publishers to sell and more ad serving impressions for advertisers, which brings in more revenue. Standards lead to scale, which benefits both publishers and advertisers.

So, as an advertiser, you should go for standard-based video ads for better campaign results.

VPAID or “Video Player-Ad Interface Definition”

  • Developed by IAB for interactions between ad units and video player focused on enabling rich interactive in-stream ad experience.
  • Enables interactivity and measuring how well your video ad does through engagement tracking.
  • Codes that runs within video players and spruce up your ad with interactive features like overlays for views to click and read more, and many others.
  • Advertisers love ads that trigger a response from the target audience and you can measure the video ads you put out there.
  • It enables you to know if your video ad is performing.

Here’s an illustration of video ad flows with VPAID.

VPAID ad tag

Why is it important for advertisers?

VPAID is important because it means you can see how individual ads are performing and devise improved ways of engaging your audiences and increasing the level of interaction with your ad.

An example of a VPAID enabled interaction would be that a user could click on an ad to view more detailed content such as a longer version of a pre-roll.

You can choose to set what time and where the ad appears within the content, with the basic functions of play, pause, close or hide, and more. Whatever action the user takes will be recorded and reported back to the advertiser.

How to optimize for maximum results? Today, most digital video placements are loaded and managed using VPAID. But, this makes it difficult to support server-side ad insertion.

Instead of VAST ad tag, many agencies merely insist on VPAID as it enables viewability, verification, and interactivity. Many agencies and advertisers also merely focused on interactivity and highly engaging ads by incorporating VPAID and MRAID for video mobile advertising.

You should also know that VPAID ads that are delivered via VAST tags are regularly referred to as VPAID tags.

So as an agency or advertiser, why should you care about this?

To get optimum results from your video ad: On top of the ad unit’s performance, you need to ensure ad serving is optimized for maximum results too. Hence, VPAID should be sent to the video player in a VAST ad response, to take care of maximizing potential video ad insertion on publishers’ side.

Why VPAID/VAST Ad is big?

The goal of these standards is to allow complete interoperability between all advanced video ads, ad networks and serving technology and players. This is to ensure that any VPAID/VAST compliant ad could be delivered through any VPAID/VAST compliant ad network/server to any VPAID/VAST compatible video player.

Two things have to be standardized to enable smooth interoperability of advanced video ads across different players environment.

  • The ad server response should be understood by compliant players—this is covered by the VAST standard
  • The advanced ad requires a standard player run-time expressed as a standard API—covered by VPAID

Here’s a diagram to show the relationships between the standards in a typical ad serving process.


In other words, with most video players adopting IAB VAST “language”, operations can quickly drop the ad into the ad server. And any video players will be able to read and display the ad correctly because they understand the “VAST language”.

As long as the video player knows how to read VAST it will be able to show the ad. It doesn’t matter where your video ads are being served.

Moreover, you can run any third-party video player ads with VAST tag because the video player will be able to understand and display it.

How it benefits Ad Ops?

  • You will be able to plug this ad into your ad server and it will just work (as long as you and your rich media vendor follow the baseline VAST format).
  • You save time in the scheduling of your video ads into a non-conforming video player.
  • You don’t have to spend time and resources on training, developing, and managing custom video ads for ad networks/servers/third-party.
  • Streamline your operations through simplification of your ad delivery.
  • Allow you to serve ads from other providers without overhauling your video player.
  • Video player developers will not waste time on customizing the development of the player for each and every new ad network or third-party.

Relationship between VPAID and VAST

VAST(video ad serving template) can be considered as an all-in-one CRM/automation platform.

If, suppose there is a requirement for customization or feature advancement, VPAID plays a role here.

VPAID helps in customization without replacing the entire VAST setup. At some point, we could call VPAID and VAST as a proxy to each other, whenever the situation demands.

Difference between VAST and VPAID

Let us dive deep into some of the differences between these two technologies.

1. Basic operation

  • VAST: Creates a communication link between the ad server and video player.
  • VPAID: Creates a bridge between the video player and video ad units.

2. Purpose

  • VAST: Ensures that video ads run in the video player in perfect coordination with the ad server.
  • VPAID: To serve video ads that can interact with the video player as per the instructions.

3. Compatibility

  • VAST: Supports all formats of standard video ads within in-stream videos across all compliant video players.
  • VPAID: Supports all interactive video formats, playback, etc. within in-stream videos across compliant video players.

4. Exchange of Data

  • VAST: Helps to provide a uniform way to exchange the data between the ad server and the video player that is independent of any technology.
  • VPAID: Offers API integration to enable video players to accept more ads independent of any complexities in video advertising.

5. Speciality

  • VAST: This technology doesn’t allow the video player to preload an ad unit before rendering the ad/media.
  • VPAID: Allows the video player to preload an ad unit before providing the ad/media.

6. Intelligence

  • VAST: Helps video players understand things like how to run the ad, what to run, extend of duration etc.
  • VPAID: Gives complete interactivity to the video ad units inside the video player. This includes expanding the ad, playing a game, submitting a form etc.

7. Control to the publisher

  • VAST: Allows publishers to take control by giving specific instructions to video players.
  • VPAID: Enables the marketer to track and measure users’ interaction with the ads

VAST 4.2

The adoption of VAST 4.2 has been a very important milestone for the ad industry. It was introduced by the IAB after multiple changes and improvements on the previous versions of VAST 3 and 2. 

VAST 4.2 adds in some important changes to earlier problems and processes like impression measurement, verifications, etc. It also brings in an important feature of “interactivity” which helps improve audience engagement. 

While VPAID does not offer complete transparency and has other issues like trust and poor user experience, this VAST update helps to streamline ad creation and delivery process. Additionally, issues like fraud are curtailed with VAST 4.2. 

The upgrade makes it possible to have a faster implementation. This is possible due to macro-based ad requests which make it possible for video players to display the ads more effectively. 

VAST 4.2 also provides more support to various OTT and mobile platforms. 

Video Ad Server – What To Look Out For?

There are 3 major things to look for when choosing a video ad server.

First, consider the loading speed of the ad server. Video ads are heavy and will require more bandwidth to load quickly. To combat this, good video ad servers usually have adaptive video streaming function that automatically delivers the video ad to the user in the most usable quality, depending on their internet connection quality.

Second, see if the video ad server offers detailed tracking. As you run video ad campaigns, there are numerous tracking metrics that you need to track and understand in order to make meaningful ad optimization. Some of these tracking metrics include video play rate, video percentile play, drop-off rate, ad viewability and dwell rate.

Lastly, look for a video a server that is simple to understand and has a support team that is able to help you when else fails. Ad servers, in general, are built to take away the complexity of ad servers, so you the advertiser can focus on managing and optimizing your ads.


Video advertising is a diverse and expanding area for online marketing. In order to be able to make valid and useful suggestions for your client, you need to know both the capabilities and the limitations of video advertising.

By being familiar with VPAID and VAST, you will know what the ads can do and where they can be placed so that they are as interactive as possible and able to be quickly distributed around the Internet.

Few things you need to know. You need to know that there are many types of video ads available. You need to know what they can and cannot do for the most part and how these video ad formats interact with the video content and the video player.

For an ad to be completely VPAID/VAST compliant it needs to interface with everything as outlined in the standard-setting document.

If you are going to start creating video ads that are non-linear or interactive, you should take a quick read through the IAB standard document.

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[All diagrams in this post are courtesy of IAB.]


Alvin is the Founder and CEO of MobileAds.com. He is a go-getter, and adventurous guy who believes in working smart to gain success in his business ventures and in life. He also founded RichMediaAds.com and MobileLanders.com.