Falkon browser: Wide-scale site breakages and severe performance lag on Linux Mint XFCE

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I am running Falkon on the latest Linux Mint XFCE. Despite updating to the latest version, the browser is failing significantly when trying to navigate modern web platforms. I want to highlight two distinct and separate issues I am facing:

  1. Broken Layouts and Site Blocks
    A large number of modern websites are completely unreadable or flat-out block the browser entirely.
  • On ChatGPT, the site loads completely broken as unstyled, raw text with zero layout formatting.
  • On Canva, I am met with an explicit “Unsupported client / Please update your browser” block screen.
  • Attempting to use the built-in User Agent Manager extension to spoof modern Chrome or Firefox strings fails to bypass these blocks or fix the broken rendering.
  1. Severe Performance Lag
    Separately from the broken page layouts, Falkon exhibits major performance issues. Ironically, while Falkon is marketed as an ultra-lightweight alternative, it causes significantly more system lag, UI stuttering, and heavy resource consumption on interactive modern sites than full-fledged browsers like Mozilla Firefox.

System Details:

  • OS: Linux Mint XFCE (Latest)
  • Falkon Version: 24.01.75
  • Installation Source: Downloaded from official website

Is anyone else seeing these separate rendering and performance issues, and is there any way to stabilize the engine?

Thank you

2

Could you give us a link to the website you downloaded it from?

On the official KDE page, the latest version is 26.04.3, and 24.01.75 isn’t listed.

3

Not seeing this on an the current version of Falkon 26.04.3., both of the sites you listed seem to work/render find. You’ll need to find a way of getting the current version, maybe Flatpak?

4

The following worked for me to log in sites such as ChatGPT and Claude AI: Try launching Falkon with the QTWEBENGINE_CHROMIUM_FLAGS=--disable-features=WebAuth environment variable flag. For example, type QTWEBENGINE_CHROMIUM_FLAGS=--disable-features=WebAuth falkon in the terminal. If that works, add the environment variable by either changing the .org.kde.falkon.desktop entry located in /usr/share/applications or launch the Application Launcher (the KDE Plasma ‘Start’ button equivalent), right click on the Falkon icon, click on ‘Edit Application’ and add the environment variable flag in the box.