Google’s Ad API is Better Than Facebook’s, But…

… with a few important omissions. Google’s tool meets four of experts’ five minimum standards


Last month, Mozilla released an analysis of Facebook’s ad archive API, a tool that allows researchers to understand how political ads are being targeted to Facebook users. Our goal: To determine if Facebook had fulfilled its promise to make political advertising more transparent. (It did not.)

Today, we’re releasing an analysis of Google’s ad archive API. Google also promised the European Union it would release an ad transparency tool ahead of the 2019 EU Parliament elections.

Our finding: Google’s API is a lot better than Facebook’s, but is still incomplete. Google’s API meets four of experts’ five minimum standards. (Facebook met two.)

Google does much better than Facebook in providing access to the data in a format that allows for real research and analysis. That is a hugely important requirement; this is a baseline researchers need. But while the data is usable, it isn’t complete. Google doesn’t provide data on the targeting criteria advertisers use, making it more difficult to determine whom people are trying to influence or how information is really spreading across the platform.

Below are the specifics of our Google API analysis:


Researchers’ guideline: A functional, open API should have comprehensive political advertising content.

Google’s API: The full list of ads, campaigns, and advertisers are available, and can be searched and filtered. The entire database can be downloaded in bulk and analyzed at scale. There are shortcomings, however: There is no data on the audience the ads reached, like their gender, age, or region. And Google has included fewer ads in their database than Facebook, perhaps due to a narrower definition of “political ads.”

[2] ❌

Researchers’ guideline: A functional, open API should provide the content of the advertisement and information about targeting criteria.

Google’s API: While Google’s API does provide the content of the advertisements, like Facebook, it provides no information on targeting criteria, nor does the API provide engagement data (e.g., clicks). Targeting and engagement data is critical for researchers because it lets them see what types of users an advertiser is trying to influence, and whether or not their attempts were successful.


Researchers’ guideline: A functional, open API should have up-to-date and historical data access.

Google’s API: The API appears to be up to date.

[4] ✅

Researchers’ guideline: A functional, open API should be accessible to and shareable with the general public.

Google’s API: Public access to the API is available through the Google Cloud Public Datasets program.

[5] ✅

Researchers’ guideline: A functional, open API should empower, not limit, research and analysis.

Google’s API: The tool has components that facilitate research, like: bulk download capabilities; no problematic bandwidth limits; search filters; and unique URLs for ads.


Overall: While the company gets a passing grade, Google doesn’t sufficiently allow researchers to study disinformation on its platform. The company also significantly delayed the release of their API, unveiling it only weeks before the upcoming EU elections and nearly two months after the originally promised deadline.

With the EU elections fewer than two weeks away, we hope Google (and Facebook) take action swiftly to improve their ad APIs — action that should have been taken months ago.

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