Introduction to falkon

Falkon is a KDE web browser using the QtWebEngine rendering engine. It was previously known as QupZilla. It aims to be a lightweight web browser available through all major platforms.

Although falkon is now part of KDE, it can be installed without KDE (with the loss of kwallet functionality).



Falkon relies on QtWebEngine. That uses a forked copy of chromium, and is therefore vulnerable to many issues found there. The Qt developers have always preferred to make releases at the same time as the rest of Qt (rather than adding emergency fixes). Now that they are keen to move to Qt6, the 5.15.3 and later Qt-5.15 releases are initially only available to paying customers. QtWebEngine is something of an exception because of its LGPL licence, but getting the git sources (with the forked chromium submodule) to a point where they will successfully build on a current BLFS system can take a lot of effort. Be aware that future fixes for vulnerabilities might be very delayed, to the extent that you might wish to consider using a different browser.

This package is known to build and work properly using an LFS 12.1 platform.

Package Information

falkon Dependencies


extra-cmake-modules-5.115.0, KDE Frameworks-5.115.0 (for karchive), and qtwebengine-5.15.17



Strictly speaking, only karchive is required to build falkon, but several other packages in KF5 can be used if they are present. To build only karchive, download that package from the directory specified in KDE Frameworks-5.115.0 and use the build instructions on that page changing the $KF5_PREFIX to /usr.


gnome-keyring-42.1, PySide2, and Shiboken2

Editor Notes: https://wiki.linuxfromscratch.org/blfs/wiki/falkon

Installation of falkon

Install falkon by running the following commands:

mkdir build &&
cd    build &&

      -DCMAKE_BUILD_TYPE=Release  \
      .. &&


To test the results, issue: make test. All tests should pass. If any fail, the full results will be in Testing/Temporary/LastTest.log.

Now, as the root user:

make install


When upgrading this package, it is possible that the contents of the application will remain empty even though everything else appears to be working properly. In this case try removing ~/.cache/falkon and restarting the program.

If you have installed Pyside2 you will want to examine hellopython.py which is in the scripts/ directory, and perhaps copy it to your home directory.



If you are on a non-x86_64 architecture and run into problems with missing text, you may wish to export QTWEBENGINE_CHROMIUM_FLAGS="--no-sandbox" prior to running Falkon.

Command Explanations

-DBUILD_TESTING=OFF: This will save a little time and space by not building the test programs, use this if you do not wish to run the test.


Installed Programs: falkon
Installed Library: libFalkonPrivate.so.3
Installed Directory: /usr/share/falkon

Short Descriptions


is a web browser which uses qtwebengine


contains functions used by falkon