Eligible ad slots can be expanded up to the device screen and partial device screen height. Experiments indicate that allowing ad slots to accommodate larger creatives typically leads to better performance compared to ad slots restricted to narrower than the available widths. This improvement is due to increased demand eligibility and click-through rates.
If you have a mobile web ad slot of 300x250 and a device with a width of 360px, a 360x300 ad may serve.
Ad slots eligible for expansion
Ad expansion for mobile web (partial screen) currently applies to backfill display and non-in-stream video ad slots. Not all ad slots are currently capable of expansion, though we’re working to increase eligibility.
How ad expansion for mobile web (partial screen) works
- Device width: The full width of the device screen (for example, 360px on a Galaxy S8 and 375px on an iPhone 6).
- Ad slot: The designated space to display an ad. It defines the dimensions for the creative.
- Container width: The width of the box containing the ad slot, whose size is defined by the publisher’s web development team. On a mobile website, container width is typically the same width as the ad slot, the same width as the surrounding content (such as the paragraphs of text before and after the ad slot), or the full width of the device.
- Note: We only allow expansion in portrait mode on mobile web.
Ad slots may expand to the width of the device, while the height may increase proportionally when appropriate to preserve the aspect ratio. However, ad slots may not always fill to the full device width and/or expand in height. There may be times when ad slots:
- Only expand to the container width. The container width is x, while device width is greater than x.
- Expand by width but not height.
- Don’t expand at all.
The ad slot will not expand to overlap existing content.
- If overlap is detected with device width expansion, but not with container width expansion, the container width will be used.
- If overlap is detected with both container width and device width expansion, the slot won't be expanded at all.
Control mobile ad expansion (partial screen)
Ad expansion (partial screen) is enabled by default. You can turn it off in network settings, though we recommend keeping it enabled for optimal performance.
- Sign in to Google Ad Manager.
- Click Inventory, then Inventory rules, and then Size settings.
- Next to “Targeting,” choose which inventory to include or exclude from the rule.
- Control which size settings are enabled on the selected inventory.
- Click Save.
Examples of ad slot expansion (partial screen)
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More examples
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Unified pricing rules and ad slot expansion
By default, Unified pricing rules apply to all sizes. However, if you have specified pricing for individual sizes and an ad slot is expanded to a size that wasn’t requested, the requested sizes will still be considered in selecting the rules that get applied. The requested size that is closest to the expanded size will be used for selecting the rule.
Example
You've requested an ad with the size 320x480 or 300x250, the ad served is 412x494, and you have three pricing rules.
- The first pricing rule targets ad size 320x480 and 1x1.
- The second rule targets size 400x500.
- The third rule targets size 300x250.
Only the first pricing rule will apply because it has the requested size that is closest to the size of the ad served.
