Alt-Tab Popup Delay in KDE

Instructions originally from

Normally KWin will wait 90 milliseconds before trying to show the popup. This makes quick switches faster since it doesn’t need to draw anything.

We need to set DelayTime=0 under the group [TabBox] in the file ~/.config/kwinrc, then reload kwin.

It’s easier to use these commmands than doing it by hand.

kwriteconfig5 --file ~/.config/kwinrc --group TabBox --key DelayTime 0
qdbus org.kde.KWin /KWin reconfigure

You can also disable the highlight window effect by going to System Settings > Window Management > Task Switcher Tab. Uncheck the “Show selected window” option.