Quick Q&A - Viewability

Posted on Tuesday 01 February 2022

Read our quick Q&A all about viewability.

What is it? 

Viewability is an online advertising metric that aims to determine whether an ad impression had the opportunity to be seen or not. It doesn’t guarantee that an ad was seen by a consumer in the same way you cannot guarantee someone turns to the page showing your advert in a magazine or newspaper.

Who does it affect? 

Advertisers need to know if their ad has had the opportunity to be seen. This is where Viewability comes in - if an ad is defined as viewable then it means that a human has had an opportunity to see the ad. This also means that Viewability levels can be taken into account when advertisers pay for impressions delivered. This is equally useful for web site owners as they can optimise their site layout and page experiences to increase the Viewability levels of their ads.

How is the IAB working with industry to address this?

The IAB has previously announced the minimum thresholds required at an impression level for an impression to be considered Viewable in a desktop/laptop environment; 

  • 50% of the ad unit in view for a minimum of 1 second for standard ad formats such as leaderboards and MPUs; 

  • 30% of the ad unit in view for 1 sec for large canvas formats such as skyscrapers and takeovers; 

  • 50% of the ad unit in view for 2 consecutive seconds for video ads. 

We work with the JICWEBS Viewability Working Group to review the state of Viewability regularly. 

When will things change?

As the mobile browsing experience is predominantly in app rather than through mobile web additional principles are required and are due to be released later this year, these will take into consideration the unique requirements for the mobile in-app environment. Once a testing environment can be created Viewability products will be tested and accredited to the same standard as the current 6 accredited desktop Viewability providers. Mobile viewability certification is scheduled for early next year.

Where can I find out more?

On the following sites:




You can also see the latest Viewability Status here.

For general questions on viewability contact [email protected]

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