How to set the default browser in KDE?

_2021 update:_ the unexpected behavior described below was actual in KDE Plasma v5.18.5, but isn't actual in 5.22.3 anymore. _2023 update:_ See also [this pull request in KDE's GitLab](https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/3324) for some details about default browser selection in Plasma 6 ([source](https://pointieststick.com/2023/11/17/this-week-in-kde-panel-intellihide-and-wayland-presentation-time/)) . ---- Linux has many ways of "marking" an application "as a default". You can check some of them using following commands: 1. xdg-settings get default-web-browser 2. ls -o /etc/alternatives/*browser* 3. ls -o /usr/bin/*browser* (some of these are symbolic links to the previous list item) 4. xdg-mime query default x-scheme-handler/https 5. grep -E 'https|html' /etc/mailcap 6. If you're on KDE grep BrowserApplication ~/.kde/share/config/kdeglobals I'm having the exact same issue as in question [How do I change the default browser that konsole opens URLs with?](https://askubuntu.com/questions/62182) . I'm running KDE 5.13.5. I did following steps: 1. Uninstall Chromium 2. Make sure all items listed above point to Firefox. 3. Go to "System Settings > Applications > Default Applications > Web Browser" (aka $ kcmshell5 componentchooser) 4. Change setting 'Open **http** and **https** URLs' to "in an application based on the contents of the URL" 5. Click an https link in Konsole 6. Install Chromium 7. Click an https link in Konsole *Actual result*: after step 5, link is opened in Firefox; after step 7—in Chromium. *Expected result*: link is opened in Firefox both in step 5 and in step 7. So KDE decided, that this particular URL ([this one](https://www.linux-apps.com/content/show.php/Redshift+Control?content=170746)) is better suited (see step 4) for Chromium than for Firefox, despite my efforts to mark Firefox as the default browser in six different ways. If in step 4 I choose "in the following application > Firefox", then everything works as expected, but I want to have it set to "in an application based on the contents of the URL", because sometimes the URLs use schemes different from http and https, e.g. mailto URLs in Konsole need to be opened by the email application, without involvement of a browser. Which method of marking a browser as default did I miss? How do I convince KDE that this URL is better suited for Firefox, which I tried to mark as my default browser? P.S. [This Debian bugs mail list thread](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=800502) suggests that Konsole does the same as xdg-open , but for me clicking on URL in Konsole opens Chromium, while xdg-open opens Firefox.