$ uname -a
Linux doctordre 6.17.0-6-generic #6-Ubuntu SMP PREEMPT_DYNAMIC Tue Oct 7 13:34:17 UTC 2025 x86_64 GNU/Linux
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 25.10
Release: 25.10
Codename: questing
Desktop Environment (if applicable):
Gnome
Problem Description:
I am using the Vivaldi browser (7.6.3797.63 Stable channel, 64-bit) on my Desktop. It, and other Qt applications seem to have no window border or drop shadow, the way my other applications do.
That’s the version I have installed (though you don’t mention package type so maybe a different package anyway), but its not a Qt themed app that I can see, seeing instead for mine
Depends: <libgtk-3-0> (>= 3.9.10)
I’m running a Qt desktop currently (on Xorg though), and just opened vivaldi and it isn’t using my selected Qt theme(s), with very different window borders to my other apps.
It may help if you’re specific with Qt apps; as your only mentioned vivaldi-stable isn’t Qt as far as I see.
Your question almost made me logout & switch to GNOME Desktop (& Wayland) session just to peek.
I got it to work but it was in a virtualbox VM. Also, I had already installed Xorg before I had fiddled with Vivaldi, so if you get errors related to X11 preventing Vivaldi from launching because you don’t have the necessary xorg/x11 packages installed, then install xorg and try launching vivaldi again with the same command-line option for ozone-platform. $ sudo apt install xorg
For QT apps on the system, setting the environment variable QT_QPA_PLATFORM=xcb should fix the problem. You’ll have to have Xorg installed for it to work with non-snap qt apps. You can add the QT variable (and others if needed) to a conf file and place it in /etc/environment.d/ to be picked by the system.
Also you may want install the following packages for more added support for running QT apps in a gnome session.
Thank you for the reply. I made a mistake in my original post, in assuming that Vivaldi is running as a Qt app. I don’t think it is! It’s the default Ubuntu snap package for Vivaldi:
$ snap list |head -1 && snap list |grep vivaldi
Name Version Rev Tracking Publisher Notes
vivaldi 7.6.3797.63 301 latest/stable vivaldi-packager** -
Therefore, my original problem statement might not be right…
Thank you for this response! My Ubuntu 25.10 system is a clean/new installation, so I bet I don’t have xorg at all (Wayland). Let me install the xorg package family and see if that solves the issue. Will report back!
I would try the --ozone-platform=x11 option first before installing any packages. The Vivaldi snap includes the x11 libs and wayland libs with it so I’m not sure if the native xorg packages are needed to make the ozone option work.
I’m just curious because I already had native xorg installed and I didn’t want to go to the trouble to uninstall all those packages just test whether ozone-platform=x11 would have worked without them. I’m hoping your experience will decide if that’s the case. HTH.
Contrary to popular belief, despite snap being a Canonical product, it is not an Ubuntu project and not exclusive to Ubuntu.
Just because Ubuntu has snap enabled by default doesn’t mean snaps are for Ubuntu.
$ snap info vivaldi
name: vivaldi
summary: A Powerful. Personal. Private. web browser
publisher: Vivaldi Technologies (vivaldi-packagerâś“)
store-url: https://snapcraft.io/vivaldi
contact: packager@vivaldi.com
license: Proprietary
description: |
The web browser for techies and people who need a browser that helps them get things done. The
user interface is fully customizable, including keyboard shortcuts, mouse gestures, and
programmable macros.
* Seize back control of your tabs with features like Workspaces, Tab Stacks, and Tab Tiling.
* Stay on top of all your emails, appointments, to-dos, and news with Mail, Calendar, Tasks, and
Feed Reader. (Compatible with IMAP, POP3, CalDAV, and Atom/RSS.)
* Jot down ideas and inspiration with the integrated Notes manager.
* End-to-end encrypted (E2EE) sync of bookmarks, passwords, notes, and more with Vivaldi for
desktop, iOS, and Android.
* Efficient built-in Tracker and Ad Blocker.
* Proton VPN.
* Compatible with most browser extensions from the Google Chrome Web Store.
snap-id: L0qubpVaz7pQaQjAbDf5RbOvfnGHTsct
channels:
latest/stable: 7.6.3797.63 2025-10-08 (301) 291MB -
latest/candidate: 7.6.3797.63 2025-10-08 (301) 291MB -
latest/beta: ↑
latest/edge: 7.7.3851.43 2025-11-11 (302) 288MB -
Per that:
contact: packager@vivaldi.com
Looks like thats what you should contact for support with this issue. Seems as though the vivaldi snap may be missing some dependencies.
All, I didn’t get a chance to test the --ozone-platform=x11 option, or to install xorg packages before Vivaldi released version 7.7. I updated my snap packages to get it, and now my Vivaldi window does have a window border! So I guess… problem solved?
Vivaldi bug report, VB-119563 [Linux][Wayland] replace old style “Chrome” decorations addresses the issue. Apparently it was fixed in the development snapshots, but just now got pushed to the new release. So, yes, problem solved.