Feedback on Tor Browser Window Size Issue

Support Tor Browser Desktop
1

I would like to report an issue regarding the initial window size of the Tor Browser. I have updated to the latest version (15.0.14 for Apple Silicon) as of UTC 2026-05-20. My computer screen has sufficient space to display the default window size of 1400x900.

However, the default window size does not correspond to the expected dimensions when accounting for Letterboxing. After opening a webpage, there is still a Letterboxing border around the initial window.

I have also consistently reproduced this issue on the Mullvad Browser.

Has anyone else experienced this problem? If so, could you provide guidance on how to resolve it?

Version

IMG-1
IMG-11460×786 115 KB

Issue Example

IMG-2
IMG-22600×1568 225 KB

Initial window size in about:config is set to default

IMG-3
IMG-32600×1568 134 KB

2

I see you have the uBlock Origin extension installed. Can you confirm the issue occurs without any third party extensions installed?

3

I just tried it, and the issue still exists even without any third-party extensions.

4

Open Firefox, disable privacy.resistFingerprinting if enabled, open TZP, screenshot it, display that screenshot here

It’s impossible to know what is going on without knowing the real available screen size with system scaling taken into account

Also feel free to screenshot your entire desktop (black out any personal info if any) with your Mullvad Browser loaded with the TZP test - don’t resize the browser in any way after opening - this way is much easier for me to work with