Viewability Tracking

This page contains legacy information. Starting from MoPub 5.13.0, the Moat and IAS viewability SDKs have been removed. Viewability tracking logic is no longer operational via these proprietary SDKs.

MoPub partnered with both Integral Ad Science, IAS (aka AdSafe) and Moat to integrate their measurement SDKs into the MoPub SDK, which was distributed to all publisher customers on August 23rd, 2017. To learn more about transacting on inventory that has the IAS and/or Moat SDKs integrated, see Viewability Support in the MoPub OpenRTB spec.



1. How is in-app measurement different than web? Why is it more challenging?

Though marketers demand viewability measurement on mobile (as they do elsewhere in digital), there are more nuances to measurement in-app. Desktop and mobile web viewability measurement can be collected solely through a JavaScript tag. However, certain characteristics of mobile app environments creates limitations for measuring viewability using only JavaScript. In order to assess and communicate the viewable state of an ad, both an SDK and JavaScript tag are typically required for measurement in-app.

The MRC has recommended the presence of an SDK in order for vendors’ measurement methodology to be accredited.

2. Which ad formats are supported?

Display formats including MRAID and HTML formats as well as VAST video. We will begin work on other ad formats after we GA the MoPub SDK with viewability however we cannot share specific timing.

3. Which tag types are supported through Moat and IAS?

There are no known issues with Moat or IAS tags and all should be supported, including wrapper tags. However we recommend reaching out to your IAS or Moat account representative for more information on how to setup your ad tags.

4. Do I need to update my desktop display ad tags to measure in-app?

IAS and Moat display ad tags can measure across both desktop and in-app. Your desktop tags will measure viewability in a mobile environment and communicate properly with the SDK. IAS has various tag types to support their product offerings and we recommend connecting with your account representative in order to learn more about the ad tag setup.

5. Are all regions supported?


6. Where can I view which apps have the viewability SDK integrated?

You can review the apps that have the SDK integrated in the MoPub Analytics Viewability Measurable dimension (coming in September)

7. Where can I track my spend?

Depending on how you transact, you can see reporting for your spend through in MoPub Analytics Viewability Vendors Response dimension (coming in September 2017) or Winning Inventory Packages dimension.


1. Can I run VPAID tags to collect video measurement?

Video measurement is supported via VAST, not VPAID. On desktop, Moat and IAS will typically include VPAID in buyer VAST tags in order to measure viewability. For in-app, VPAID support is less common across multiple supply sources, therefore IAS and Moat have both developed solutions to measure viewability through VAST. See more below.

2. Can I use the same desktop video tags in-app?

No. VPAID measurement, which is typically used to measure video in desktop, is not supported in-app. VAST video measurement in-app requires buyers to add an <Extension> to their VAST tag. See more below

3. How do I measure video on MoPub?

For IAS, DSPs should work directly with their IAS account representative to integrate the VAST <Extension>.


Currently Moat is running a beta with select DSPs in order to update VAST tags with the <Extensions><Extension>.

<Verification Vendor>
<ViewableImpression id>


DSPs and customers should work directly with their IAS account representative to integrate the VAST <Extensions><Extension>. Please reach out to your IAS team in order to learn more.


Bid Response

1. Do I need to change anything about my bid response to make sure MOAT/IAS communicates with the SDK properly?

Buyers that support viewability inventory packages are required to submit the bid request deal ID in the bid response when they are responding with a campaign that is measuring viewability. If you do not have a campaign for viewability, your bid response may fallback to an open auction bid response. DSPs that are ingesting the viewability vendor flag must declare the name of the vendor tag that is collecting viewability measurement (ias or moat)

2. What are the differences between the deal ID and viewability vendor flag and why should I use one over the other?

They both represent the same exact inventory. As a buyer, you can choose how you target inventory that’s viewability enabled – either through Inventory Packages via a Deal ID or by ingesting a flag in the bid stream. Buyers with MOAT & IAS inventory packages enabled will receive multiple deal IDs in the bid request. Buyers who ingest either signal in the bid stream will benefit from the OpenRTB approach of ingesting information, including it feeding into your own optimization, front-end and bidding systems.

3. We currently have IAS’ pre-bid viewability solution implemented in desktop. Is this available?

IAS does not support pre-bid for viewability in-app at this point in time. Please reach out to your IAS team for more information on their in-app pre-bid product offerings.

Last updated June 15, 2020

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