Signal App: Secure Screen Sharing

Stefan Thies
2 min readJan 11, 2021


Signal is a very secure messenger app. I love Signal to call my friends and colleagues. For a long time, I missed Group-Calls, but the December 2020 release of Signal App introduced “Group calls”. Finally!

Still, I missed a feature to share my PC Screen with other users, e.g. for work or Home-Schooling. So I’ve checked the Signal Desktop App. Unfortunatly the Desktop App has no “screen-sharing” button :( — at a first glance there is no native support for THE feature I want. Then I discovered the option to chose a different Camera Device in the call settings. Bingo! The camera devices listed my OBS virtual camera. When I start OBS Virtual Capture, everybody can see my screen in the viedeo-call!

You may ask why is Screen-Sharing via Signal Desktop such a cool feature? Well, there is more than a single answer to it:

  1. No privacy concerns. Signal implements secure end-to-end encryption protocol and you don’t need to be afraid of unwanted data sharing policies — unlike WhatsApp, Facebook, Google or any other commercial data miners
  2. No commercial licenses, unlike WebEx, GoToMeeting, MS Teams …
  3. Perfect for regular meetings with a group of people — like a class room or team at work
  4. OBS and Signal are transparent open-source projects

So let me show step-by-step, how screen sharing works with the Signal Desktop App:

  • Create a Signal Group in the Signal App
  • Invite Group Members

On your PC:

Now, it is time to make the first secure group-call for a presentation or work meeting:

  • Start OBS Studio and activate the virtual camera capture
  • Call your Signal Group
  • Switch Camera setting in Signal Desktop App to “OBS virtual camera”
  • All users should see your Desktop and everything is end-to-end encrypted

Signal is a great tool for secure personal communication. With my little setup, you can turn Signal Desktop into a productive tool for work or school. Enjoy!



Stefan Thies

Freelancer, DevOps & big data consulting. DevOps Evangelist at Sematext -Full-Stack Observability at your fingertips.