AllSides
AllSides Technologies Inc., (DBA as AllSides) is an American-based company that estimates the perceived political bias of content on online written news outlets, and then presents different versions of similar news stories from sources AllSides rates as being on the political right, left, and center, with a mission to show readers news outside their filter bubble. John Gable, a former Republican operative, is the main founder, CEO, primary owner and investor. Company 
AllSides was launched in September 2012 by Republican John Gable, who is the main founder, CEO, primary owner and investor. After working as a Republican operative and then Silicon Valley manager, he recruited software developer Scott McDonald (now CTO) to help him start the organization. AllSides staff self-report their political leanings. The original AllSides Inc. disbanded, and in 2016 AllSides Inc.'s assets, including AllSides.com and its mobile application, were purchased by AllSides LLC. In 2023, citing a desire to grow and accept outside funding, AllSides LLC changed its company structure and legal name to AllSides Technologies, Inc. To align with and protect its mission, it was established as a public benefit corporation. Rating system 
AllSides uses a "multi-partisan" methodology first developed by conservative professors Timothy Groseclose and Jeffrey Milyo. AllSides focuses only on online written content (not TV, radio or podcasts). It rates sources on a five-point scale from -9 (farthest left) to 0 (center) to 9 (farthest right), breaking these into five categories: Left, Leans Left, Center, Leans Right, and Right. Each source is rated by a combination of methods, including editorial reviews by a multi-partisan staff panel, and blind surveys taken by thousands of people of different (self-reported) political biases. AllSides uses these ratings to produce the AllSides Media Bias Chart. The ratings also appear alongside news articles posted to the website, allowing readers to identify the source’s potential bias. The AllSides Media Bias Chart was mentioned in the book Why Media Matters. Criticisms 
Jake Sheridan from Poynter Institute notes the controversy surrounding bias rating charts in general and recommends readers consider the reliability of sources in addition to possible bias. Sheridan also discusses Ad Fontes, an organization that evaluates both reliability and bias for a wider array of media outlets than AllSides. Educational content 
AllSides partnered with Living Room Conversations, a nonprofit founded by Joan Blades, on educational content through a related organization called AllSides for Schools. Gable, Blades, and their associated organizations have produced lesson plans for schools on how to navigate political conversations and helped create Mismatch, a platform to connect students who differ politically and geographically. See also 

 Ad Fontes Media
 Media Bias/Fact Check
 NewsGuard
 Our.News

References  

Internet properties established in 2012
Media bias