Ad Fontes Media

Ad Fontes Media, Inc. is a Colorado-based media watchdog and public benefit corporation, primarily known for its nonpartisan Media Bias Chart. The organization was founded in 2018 by patent attorney Vanessa Otero with the goal of combating political polarization and media bias. Ad Fontes Media uses a panel of analysts across the political spectrum to evaluate articles for the Chart. The chart markets its analysis to advertisers looking for third-party rankings of news sources in assessing brand safety, and it is generally considered a simple guide but not a solely authoritative source for understanding media biases.