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Blacklight Updated With New Tracking Info and Caching Options

Our privacy scanner can now return more up-to-date information

Illustration of the Blacklight logo, with a purple swish behind it. On the bottom right hand corner is a star-shaped sticker with the words "UPDATE" and a wrench icon.
Gabriel Hongsdusit

If you’re using Blacklight for an ongoing research project or data collection, please read this announcement

Blacklight, The Markup’s real-time web privacy detector tool, has exposed privacy violations on COVID-19 vaccine websites, spurred legislative action, and made more than 10 million scans. Starting March 20 2024, users can begin to take advantage of two improvements.

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Updated tracker list

Blacklight identifies online trackers by comparing a website’s network activity to the Duck Duck Go Tracker Radar, a “tracker list” which classifies third-party domains by purpose. We’ve updated the version of Tracker Radar we use, bringing you the most up-to-date information on trackers across the web.

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New cache override feature

Since its inception, Blacklight has saved the results of scans for 24 to 48 hours, returning the saved version of the scan if the same site is queried within that time frame. This process, called caching, improves Blacklight’s performance but may also show out-of-date information. We’ve added the option to ‘force’ a request, overriding Blacklight’s cache and triggering a brand-new scan of the page. This option is off by default, and can be set from the ‘options’ dropdown.

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What you need to know

Blacklight may show more trackers after these changes, since the updated list will contain new trackers that aren’t currently being captured. Additionally, users who are making privacy changes to their own sites will be able to quickly verify that privacy enhancements have taken effect, using the force feature.

As we continue improving Blacklight, we want to hear from its users. Send us a message at to let us know how you use the tool, and what features you’d like to see down the line.

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