Citizen Browser project's Split Screen tool shows Facebook's different News Feeds for Trump and Biden voters, based on data from 2,500+ users across the US
a tool that lets you see other people's feeds, based on our national panel of Facebook users. Brought to you by @suryamattu and @sammorrisdesign: https://themarkup.org/... Dan Froomkin / @froomkin : This is not about what they CLICKED on. This is about what Facebook CHOSE TO SHOW THEM. Gotta bookmark this. https://twitter.com/... Tony Romm / @tonyromm : markup is out here doing some of the most creative stuff on the tech beat https://twitter.com/... @alfredwkng : Hey, everyone should check out The Markup's Split Screen, which shows just how polarized real Facebook feeds from more than 2,000 panelists can get: https://themarkup.org/... https://twitter.com/... Rat King / @mikeisaac : this is a true public service https://twitter.com/... Adel Brown / @adelbrown : Not a surprise but it's landing differently for me when I can see the side-by-side. Deeper sadness and curiosity about how this divide of “truth” can be bridged. https://twitter.com/... Angie Waller / @angiewaller : Excited to announce a project I have been part of since joining @themarkup has launched! Split Screen, designed by @SamMorrisDesign, lets you compare what stories, hashtags, and groups are shown to different people on Facebook... https://twitter.com/... Jon Keegan / @jonkeegan : The resulting tool, Split Screen (https://themarkup.org/...), shows news sources, news articles, hashtags, and recommended groups from more than 2,500 actual peoples' feeds. And it is updated daily. Please note the *extensive* methodology here: https://themarkup.org/... 4/5 Jon Udell / @judell : This project, from the @themarkup, is really well done. Prior art includes @jonkeegan's Blue Feed, Red Feed from 2016. What are we doing to do about it? https://themarkup.org/... Jon Keegan / @jonkeegan : Really excited for our launch today of Split Screen, our look at what different groupings of people find on their Facebook feeds, powered by #CitizenBrowser data. https://themarkup.org/... 🧵 1/5 Aaron Sankin / @asankin : During the first month of 2021, two of the top four groups Facebook recommended to Democrats were promoting the Lincoln Project. https://themarkup.org/... https://twitter.com/... Nicholas Dawes / @nicdawes : Despite all the confident assertions, it's hard to know what effect algorithmic curation has on news consumption. A new tool from @themarkup lets you see the news feeds of Trump and Biden voters, based on data from more than 2,500 people. And yes, it's 😱 https://themarkup.org/... Dr. Julie Posetti / @julieposetti : This is quite genius from @themarkup: Split Screen, an interactive tool that lets you see what the Facebook filter bubble looks like through the wildly different news feeds of Trump & Biden voters. A data-led illustration of how our feeds are manipulated. https://themarkup.org/... @simplysecureorg : 🔍New tool from @themarkup! Split Screen lets you see what the filter bubble on Facebook really looks like. See the wildly different news feeds of Trump and Biden voters, based on real data from more than 2,500 people across the U.S. https://themarkup.org/... David Bauer / @davidbauer : Blue Feed, Red Feed by @jonkeegan was one of the most eye-opening interactives I've ever seen. Sadly no longer maintained. https://graphics.wsj.com/... Now at @themarkup, he brought it back to life, even better than before. https://themarkup.org/... Craig Newmark / @craignewmark : New from @themarkup: Split Screen, a tool that lets you see for the first time what the filter bubble on Facebook really looks like.Examine wildly different news feeds of Trump and Biden voters, based on real data from more than 2,500 people across the US https://themarkup.org/... Justin Hendrix / @justinhendrix : .@themarkup has built a tool that shows snapshots from the Facebook feeds of Citizen Browser panelists to illuminate how Facebook's recommendation algorithm siloes information on the platform: https://themarkup.org/... https://twitter.com/...
Context & Ripple Effects
Split Screen is the first public output of the Citizen Browser Project The Markup launched with The New York Times last fall to measure how Facebook and YouTube algorithms actually serve content. Earlier corpus work showed why instrumentation matters: a November survey of just 173 users' feeds found 54% saw no news within their first ten posts, and January panel data caught 12 political groups still ranking among Facebook's top recommendations even as the company promised to stop recommending political content.
The tool's significance, as Dan Froomkin's framing in the coverage makes explicit, is that it measures what Facebook chose to show rather than what users clicked — moving the polarization debate off Facebook's own disclosures and onto an independent panel of more than 2,500 U.S. users.
First-order effects
- Journalists and the public can now directly compare real Trump-voter and Biden-voter News Feeds side by side, replacing anecdote with panel-based evidence of algorithmic divergence.
Second-order effects
- Facebook's practice of steering the narrative through self-released data — the basis of the November link-post debate in the related coverage — loses its monopoly, since Citizen Browser generates comparable measurements without the company's cooperation.
Third-order effects
- If independent instrumented panels become the standard for auditing feeds, platform accountability shifts from voluntary disclosure toward continuous third-party measurement, raising the bar regulators would apply to recommendation systems.
The trend: Platform accountability is shifting from companies disclosing their own engagement data to independent researcher panels that measure what algorithms serve users directly.