macOS Big Sur: restore the old windows title bar

In macOS Big Sur, the upper part of the windows adopts a new style where the title and the toolbar are merged at the same level. A thinner bar also and sometimes inconvenient to point to move your window because of the clutter of icons (see also macOS Big Sur: these regressions that can annoy).

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If you don't like Big Sur's new title style and want to revert to how it looks in Catalina:

defaults write -g NSWindowSupportsAutomaticInlineTitle -bool false

and relaunch Finder. pic.twitter.com/MeTxgDYLHk

— Daniel Martín (@dmartincy) November 7, 2020

the developer Daniel Martín, we can easily go back to the previous style thanks to this command to copy paste in the Terminal (to be kept under the elbow while the release of Big Sur should not delay):

defaults write -g NSWindowSupportsAutomaticInlineTitle -bool false

Then force Finder to quit (or log out) to get the new presentation. You will also see the window folder icon again, which in Big Sur is hidden by default and only revealed when you approach the mouse.

Ditto with the Mail application, if you quit and relaunch it you will reactivate the old style bar. In other applications without a title bar, the change is manifested by slightly smaller icons in the toolbar.

To go back to Big Sur style, type the same command line ending with true instead of false.