The Markup's website privacy inspector tool, Blacklight, has expanded its capabilities to detect tracking pixels from TikTok and X (formerly Twitter) in addition to Google and Meta, which it had previously detected. Since 2020, over 18 million scans have been run using Blacklight. The new features were developed by a group of computer science students from Brandeis University with the support of The Markup's product team. Blacklight can now report on the presence of TikTok and X pixels when scanning a website and provide more detailed information about the data being passed through these pixels.
Written by the local model on 2026-09-05,
using this article's own text rather than the other coverage of the
same event (that is the story summary below).
Story summary
The Markup's online tool, Blacklight, which tracks website privacy, has been updated to detect two new types of tracking pixels: those from TikTok and X (formerly Twitter). This means that when users scan a website with Blacklight, it will now report if it finds either of these pixels. The detection feature was added after over 18 million scans since its launch in 2020, which previously only identified pixels from Google and Meta. Tracking pixels are small pieces of code that collect user data, including browsing history, purchases, and searches, to build detailed profiles for targeted advertising. This data can also be used for other purposes. The update aims to increase transparency and awareness about online tracking, which has led to lawsuits and increased scrutiny in the past.
Written for “TikTok Data Collection Practices” on 2026-09-05,
grounded in this article and the 0 other(s) covering the same event.
Why this leaning score
This article does not take a side on a contested political
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answer rather than a gap: a match report or a rescue can be warmly
or critically written without being left or right, and scoring it
anyway is how approval of a subject gets recorded as a political
position.
No political leaning scored for article 4377 · logged 2026-09-05
Since 2020, readers have used Blacklight, our pioneering website privacy inspector tool, to run more than 18 million scans.
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readers → use → scans
Previously, Blacklight detected tracking pixels from Google and Meta.
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Blacklight → detect → Google
Today, we’re announcing that it can scan for two more digital trackers: TikTok and X pixels.
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it → announce → trackers
A tracking pixel is a small piece of code added to a website that sends information about the site’s users to the platform that operates the pixel.
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that → track → pixel
That can include details of a user’s activities, such as their browsing activity, purchases and searches.
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That → include → activity
A website that embeds a pixel often does so to inform its advertising campaigns on the platform that create the pixel.
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that → embed → pixel
When its pixel is embedded across many websites, the platform can compile a user’s data to build a detailed profile of their interests, behavior and other personal information.
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platform → embed → interests
These profiles allow other businesses to buy ads from the platform to target categories of users — though this data can also be used for other purposes.
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data → allow → purposes
When you look up a website in Blacklight, it will now report if it finds the TikTok pixel or X pixel.
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it → look → pixel
More detailed information about the specific data being passed through pixels is also available by clicking on “Learn more” in the top right of the results, then clicking the link to “download an archive.”
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information → pass → archive
To develop these new features, we partnered with a group of computer science students in Brandeis University’s Capstone in Software Engineering course.
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we → develop → course
These students – Yiyou “Felix” Fan, Jiawen “Zena” Hu, Hengye Li, Hongchen “Steven” Yang and Yiquan “Frank” Zhang – researched and developed the features with the support of our product team.
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students → research → team
Blacklight’s pixel detection features have already powered our Pixel Hunt investigations, which revealed that sensitive personal user information was being shared from government websites with Meta and Google, leading to lawsuits, removal of pixels from sites and increased government scrutiny.
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information → power → sites
These new features give a fuller picture of the digital privacy landscape by exposing tracking pixels from two more companies.
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features → give → companies
We hope these new features will help you better understand what happens to your data as you navigate the internet.
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you → hope → internet
While Blacklight can’t say exactly what companies like TikTok and X do with our data, it can provide a starting point for deeper investigation into how that data is stored, shared and used across the web.
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data → say → web
Do you have questions, suggestions or need help understanding your Blacklight results?
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you → have → results
You can always reach us at blacklight@themarkup.org.
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You → reach → blacklight@themarkup.org
