• Ad Observatory

    See our analysis of Facebook advertising, and search for messaging trends, microtargeting, views by state, and more!

  • Ad Observer

    Help out by contributing your Facebook and YouTube ads by installing the Ad Observer plug-in tool.


  • An Audit of Facebook’s Political Ad Policy Enforcement

    In the first known study to quantify the performance of Facebook’s political ad policy enforcement at a large and representative scale, researchers found that when making decisions on how to classify undeclared ads, Facebook often missed political ads while falsely labeling others as political. The political ads that Facebook misses also disappear from its public archive, putting them out of reach for public scrutiny.

  • A Standard for Universal Digital Ad Transparency

    Proposal spells out criteria that trigger transparency requirement, with ad data to be collected by government agency

  • Understanding Engagement with (Mis)Information News Sources on Facebook

    Across the political spectrum, posts from news sources that regularly traffic in misinformation have a statistically significant and large engagement advantage–by a factor of six–-over posts from news sources that have a record of factualness.

  • An Analysis of United States Online Political Advertising Transparency

    In total, ads with political content included in these archives have generated between 8.67 billion - 33.8 billion impressions and that sponsors have spent over $300 million USD on advertising with U.S. political cont

  • A Security Analysis of the Facebook Ad Library

    Several weaknesses enable a malicious advertiser to avoid accurate disclosure of their political ads. We also propose a clustering-based method to detect advertisers engaged in undeclared coordinated activity.

Data sets

  • Ad Observer Data

    Public dataset of political ads observed by users of our browser extension.

  • Facebook Ad Library Data

    Public dataset of ads we have collected from Facebook’s Ad Library for the US, Canada, and the UK. Access is limited to verified academic researchers and journalists who have access to Facebook’s Ad Library API, and managed by Harmony Labs.

  • Facebook Transparency Reports

    Public dataset of historical transparency reports published by Facebook.


  • Github

    Open-source code for Ad Observatory, our analysis and data collection.

Tutorial Videos