Google Chrome – Keyboard Shortcut to Close Other Tabs

As other have mentioned, there is no built-in keyboard shortcut. However, we can work some magic with AutoHotkey. I am going to use the Backspace key to close the highlighted Taskbar window:

LastNumber := ""

~*1::LastNumber := "1"
~*2::LastNumber := "2"
~*3::LastNumber := "3"
~*4::LastNumber := "4"
~*5::LastNumber := "5"
~*6::LastNumber := "6"
~*7::LastNumber := "7"
~*8::LastNumber := "8"
~*9::LastNumber := "9"
~*0::LastNumber := "0"

*BackSpace::
    IfWinActive, ahk_class TaskListThumbnailWnd
    {
        WinKey := "LWin"
        if (GetKeyState("RWin"))
            WinKey := "RWin"
        
        SendInput, {Enter}
        WinClose, A
        
        SendInput, {%WinKey% Down}{%LastNumber% Down}{%LastNumber% Up}
    }
    else
        SendInput, {BackSpace}
    return

Instructions:

1. Press and hold the Windows key down. Do not release it until instructed!

2. Press a number key until the target window is highlighted.

3. Press the Backspace key. The highlighted window will be closed! If the there is only one window left, then that window will be activated, otherwise the window group list will return.

4. Repeat steps 2 to 3 to close more windows.

5. Finally, release the Windows key to be done.

This should work with Taskbar thumbnails enabled or disabled (as shown in the question).

Chrome and all its clones have lost the ability to warn before doing that action, even Microsoft Edge.

It was previously possible to block with the extension "Google Chrome Toolbox Extension" which has been forcefully discontinued by Google. It used to be possible by pinning a website that demanded permission before close, but even this didn't work when I tested just now.

So I'm afraid that the answer is negative: There is no way to block that action, not even by an extension. The Chrome developers have blocked all the known methods, intentionally or not. (I admit that there might exist new methods that I'm unaware of.)

If that option is very important to you, the only solution is moving to another browser. For example, Firefox has an option for "Warn you when closing multiple tabs", and is compatible with Chrome extensions, so you won't lose your favorite ones when converting.