Size Mapping for Responsive Ads Using Ad Manager Tag Generator & Tester

“Responsive” means the ad unit adapts automatically to the device where it’s being served. For example, ad_top_atf serves as either a 970×90/728×90 ad unit on desktop and transforms into a 300×250/320×50 on mobile. AdSense has this option when choosing the Ad Unit size, which they call a “responsive” size. If you use Google Ad Manager tags and want to do the same, you may do Size Mapping.

Google Ad Manager can handle the responsive behavior of the ad units by using Size Mapping. This gives publishers assurance that only appropriate sizes can be served depending on the device a visitor is using. In the old days, we used to insert codes manually, which was prone to many human errors, just to run Size Mapping for responsive ads. Now, you fill in the values using Ad Manager Tag Generator & Tester, and the tool generates the codes for you.

Let’s look at how to set it up below:

Size Mapping Setup Part 1

Step 1: Set the viewport minimum widths (in pixels) you will follow. Example:

Device	Minimum Width
Desktop	992 px
Tablet	768 px
Mobile	320 px
Other	0 px

Step 2: Decide on how many Size Maps you need. Depending on your site layout, you can set one Size Map that can be applied to multiple locations or spots. Here’s an example:

(top)

Mapping 1:

992×0 – 970×250, 970×90, 728×250, 728×90, 300×250, 336×280, 1×1

768×0 – 728×250, 728×90, 300×250, 336×280, 1×1

320×0 – 300×250, 320×50, 320×100, 1×1

0x0 – 320×50, 1×1

(sidebar)

Mapping 2:

992×0 – 300×600, 300×250, 336×280, 160×600, 1×1

768×0 – 300×250, 336×280, 160×600, 1×1

320×0 – 300×250, 320×50, 320×100, 1×1

0x0 – 320×50, 1×1

(mid-content)

Mapping 3:

992×0 – 728×250, 728×90, 468×60, 300×250, 336×280, 1×1

768×0 – 728×250, 728×90, 300×250, 336×280, 1×1

320×0 – 300×250, 320×50, 320×100, 1×1

0x0 – 320×50, 1×1

Here’s what it means: look at mapping 1 (top).

If the device is at least 992px wide, regardless of the height, these are the sizes eligible to serve: 970×250, 970×90, 728×250, 728×90, 300×250, 336×280, 1×1
If the device is at least 768px wide but less than 992px, regardless of the height, these are the sizes eligible to serve: 728×250, 728×90, 300×250, 336×280, 1×1
If the device is at least 320px wide but less than 768px, regardless of the height, these are the sizes eligible to serve: 300×250, 320×50, 320×100, 1×1
For any device smaller than 320px wide, these are the sizes eligible to serve: 320×50, 1×1

We are setting up another Size Map for the sidebar and middle because certain sizes are inappropriate for those spots. For example, you can’t serve a 300×600 in the middle of the page and can’t do 728×90 on the sidebar. Therefore, you need to declare which sizes are appropriate.

Feel free to create as many Size Maps as necessary. You can also re-use the same Size Map for multiple ad units, where applicable. For example, if you run three different ad units mid-content, you can assign the same Size Map for those three ad slots so they follow the same set of rules.