Welcome to

Use the extension to see why your privacy is in danger.

One big circle surrounded by six smaller circles which are connected with the big one through lines

What is Lightbeam?

Firefox logo Addon for Mozilla Firefox (Installation)
Gitlab icon Open Source (Source Code)
Recording icon Records websites and third party requests
Graph icon Visualization


  • Recording of visited websites and their third party requests
  • Visualization of recorded data as a graph
  • Export of the recorded data
  • Fuse Mode: Fuse multiple third party requests into one node
  • All recorded data stays on your device
  • Languages: English and German

Latest News

Announcement: Lightbeam moves to Codeberg (November 28, 2023)

Lightbeam is a tool which has the purpose (among others) to show that you need to protect your privacy. The addon itself is also caring for your privacy and only saves recorded data local in your browser.

Gitlab which still hosts the repository of Lightbeam uses Cloudflare to protect its website from bots and Cloudflare makes it impossible to log in to the platform in some cases when you use a browser with addons that increase your privacy. That is the reason why I decided to move the repository of Lightbeam to a new home: Codeberg. Codeberg is maintained by a NGO and doesn’t use trackers, third party cookies or anything similar so it is the perfect place for Lightbeam.

There is already a repository for Lightbeam on Codeberg while the old one still exists on Gitlab. The plan is to replace all URLs on this website and in the addon itself until the end of this year. Another todo is to create an archive of the old repo and leave a note so everyone knows that the development is taking place on Codeberg.

New Release: Lightbeam 2.4.0 (September 6, 2023)

Some persons shared useful ideas how to improve Lightbeam on Gitlab and this release contains these improvements.

You can now filter the first parties by choosing different options in a new sidebar. These options affect which first party websites are shown. So if you decide to show only 50 websites this means that Lightbeam shows only 50 first party websites. Because first parties may contain a different number of third parties the graph could contain much more than 50 nodes. It would be technically possible to limit the nodes to a specific number but this would cost more performance, so I decided not to do so.

The drawing of the graph is an ressouce-intense process. If you recorded many websites it could even be that Lightbeam crashes. That’s why Lightbeam now shows a warning when there are more than 200 nodes.

Additionally to these changes there are more features. With the newest version it is possible to import data that you exported before. This is not only helpful to make testing of Lightbeam easier. It also gives you the opportunity to prepare some special cases that you can just import at every time and show to other people.

And there are other little changes:

  • Data can also be saved in a fused version.
  • Export contains metadata (e.g. version of Lightbeam used to export the data).
  • Only “real” third parties are shown (before also URLs like abc.domain.de were shown as third parties when they were called from domain.de although they aren’t third parties in this case).
  • The tooltip shows the number of requests.

Why you should try Lightbeam

People who use a browser without any extensions often don’t have a clue what’s going on while they are browsing through the web. They don’t know that these websites are contacting other servers for additional ressources, tracking etc.

Lightbeam can show them that many websites make requests to the same third party and that some third parties - like Google - are present on the majority of all websites. This leads to the insight that those third parties know which websites you are visiting. What they do with this knowlegde - or data - is a different thing.

A little background


Originally, the addon Lightbeam was developed by Mozilla since 2017. Two years later they stopped the development but their repository was still available.

Unfortunately, they didn’t offer the addon on addons.mozilla.org (AMO) anymore and I - Christoph Klassen - heard about that fact from people at Digitalcourage. Because some of them used that addon to show how differenct websites are connected and to give other people some idea of it I decided to revive Lightbeam.


One main goal with Lightbeam is to make it stay available. That means that if conditions for addons change I will adjust Lightbeam so Mozilla won’t throw it out from AMO. The next main goal is to keep it up-to-date so I will update the libraries, replace deprecated methods and so on.

New features don’t belong to my goals but that doesn’t exclude that I will implement some. The fuse mode is one new feature that I implemented since I started maintaining Lightbeam.