Viewability best practices

Use the viewability best practices list below to learn about which areas you should address for better viewability results. 

Page length

Short form content yields higher viewability, therefore set pages to have only one fold. If you must have longer form content, enable infinite scroll. Learn how to place tags on a page with infinite scroll.


Latency is caused from a number of issues, one of which is passbacks. The reduction of latency from passbacks increases viewability. The elimination of passbacks improves viewability metrics.

Lazy loading

Also known as Smart Loading, means serving ads only when it’s necessary. For example, serving an ad towards the bottom of the page only when a user scrolls down the page. Lazy loading enables pages to load faster, reducing latency and CPU consumption. Learn more about lazy loading

We recommend using this code sample as an implementation guideline for Google Publisher Tags, since other forms of implementation might trigger multiple ad requests that don’t lead to a rendered creative in the browser (which will further reduce your viewability metrics).

Lazy loading is enabled by default for publishers using the legacy Ad Exchange tag.
  • Infinite scroll
    Infinite scroll, a form of lazy loading, is when the browser scroll bar keeps scrolling but never reaches the bottom of the page, which causes the page to grow with additional content.

Lazy loading can affect your viewability.

  • If used properly, lazy loading can increase the overall viewability percentage. In cases where a user didn’t scroll down, for example, the Below-the-fold ad slots never loaded, fewer ad requests are made.
  • However, if the ad size is too large or loads too late, for example, when the user scrolls down faster than the ad loads, the user won’t be able to view the ad.
As a user scrolls, hiding previously rendered slots or showing previously hidden slots isn't the proper implementation of lazy loading and doesn't improve viewability.

Responsive design

Build responsive ads so that they fit the particular browser used to view those ads. This provides a good user experience, regardless of which device (mobile, tablet, or desktop) they select to view your content and ads.

Try the following best practices:

Enhance site viewability

First, let’s review what we must measure before an ad impression is counted as viewable.

  1. A user must navigate to an area of the page where 50% of the ad’s pixels are visible in the browser window.
  2. The user must pause or proceed slowly enough that the ad is on screen for 1 continuous second. Scrolling past an ad too quickly does not count.
  3. The ad must be rendered when the user navigates to it.

With this in mind, we reviewed Active View data across the AdSense network and compared a broad range of site designs with high and low viewability. To help maximize the number of viewable impressions generated by your site here are some suggestions based on our research.

General ad placement
  • Content: Produce appealing content and page design that users want to consume and engage with.
  • Ad Placement: Place ads in line with the main content or in content-rich areas of the site. When choosing ad placements it’s important to consider the user experience. Avoid placing ads in areas with little or no unique content or overloading certain areas of the site with too many ads.
  • Speed: Ensure page loads are fast and reliable, including ad rendering time. Use of asynchronous ad tags is recommended, and speed optimization tools such as Google Pagespeed can be used to analyze and optimize site performance.

Before making any ad placement decisions we suggest reviewing the Google Analytics screen resolution report to understand where your site’s page fold is most often located. To access the screen resolution report in Google Analytics: visit the Audience tab, expand the Technology category, click Browser & OS and then select Screen Resolution as the primary dimension. After understanding how your site is viewed, review the suggestions below to increase the opportunity of your ads becoming viewable.

Above-the-fold (ATF) placements
  • Content: Offer engaging content on the first page and try to make as much of it viewable without scrolling (by using wider, shorter, or content-rich page design). This will ensure that users have time to read, digest, or interact with ATF content and ads.
  • Ad placement: Consider placing ads near the bottom of the screen (right above the fold). This placement has shown the highest viewability rates from our data. Ads placed just below the top navigation bar have a higher viewability rate than those placed at the very top of the page. At the same time, don’t forget about user experience. Too many ads above the fold will make your page appear cluttered and your visitors may leave the page too quickly.
  • Speed: Ensure your ads load quickly so users don’t scroll past them before they load.
Below-the-fold (BTF) placements
  • Content: Create engaging above-the-fold content that invites your visitors to scroll down the page to see what is below the fold. This will lead them down the page revealing BTF ads. Place visible headlines of the next article or story near the bottom of the top fold to encourage the user to find out what’s further down the page.
  • Ad placement: Ads placed on the left or right side have higher viewability rates than those placed in the middle. Additionally, placing ads in a separate column from the content can keep the content column clean and unobstructed, and may increase the chance that the user proceeds down the entire page.

Quality control

Test and iterate as part of the redesign process. Each site is different as viewability depends on the content, vertical, and users’ behavior on the site.

Insights from Think with Google’s “The Importance of Being Seen”

To optimize your viewability, here are some ideas to keep in mind:

  • Position on the page matters--the most viewable position for an ad is right above the fold, not at the top of the page.
  • The most viewable ad sizes are the vertical sizes units, for example, 160x600.
  • Above-the-fold is not always viewable, while many below-the-fold impressions are viewable.
  • Content that holds a user’s attention has the highest viewability.
In recent studies, mobile sites that loaded within 5 seconds, versus 19 seconds, were observed to have 25% higher viewability. Learn how to improve your mobile content with the Google Ad Manager Mobile Web Speed Toolkit.

Watch related Publisher University training

Was this helpful?
How can we improve it?