By Dan Moren

September 21, 2020 8:48 AM PT

Enabling the Debug menu in Safari 14 on Big Sur and Catalina

Note: This story has not been updated since 2020.

Update 9/22: After further testing, it seems the standard defaults write command does continue to work in macOS Catalina with Safari 14, though the Big Sur beta may require the method mentioned below.

Update 2 9/22: Oh, what a tangled web we weave… It turns out it’s a little more complicated than the post below makes it sound. Developer Jeff Johnson has written a great blog post explaining exactly what’s going on here: it involves a combination of macOS sandboxing and System Integrity Protection. In certain cases you can use defaults write in Big Sur—if you’ve granted Terminal access to your disk in the Security & Privacy pane in System Preferences.

With new Apple software updates come new questions, and reader Martin has one related to an old tip of mine:

Thanks for the great tip on fixing tab behavior.

However, the directions on how to get the debug menu no longer seem to work with Safari 14. Any idea on how to enable nowadays?

Great question! The tip in question deals with making new Safari tabs open at the end of the window rather than next to the active tab, a behavior that many users prefer. Thus far you’ve been able to change that setting in Safari’s hidden Debug menu, but Martin’s right that Safari 14 adds some additional complications.

It seems that the trusty defaults write command does no longer allows users to enable Safari’s Debug menu. So I enlisted my pal, dicemaster, and developer extraordinaire James Thomson to help me figure out this puzzle.

First, just to note: it seems that, having already had the Debug menu enabled on my iMac running Catalina, it’s persisted with the update to Safari 14. But if you want to newly enable it in Safari 14 on Catalina (or on the Big Sur beta), you’ll need to use the following process.

So, with the Safari 14 update, the preferences file that you need to edit to enable the Debug menu no longer resides in the Preferences directory of your library¹, and the defaults command thus can’t edit it. However, it’s still possible to make the Debug menu show up—it’s just a little more complicated.

You’ll want to navigate to ~/Library/Containers/com.apple.Safari/Data/Library/Preferences/—note that if you’re trying this on the Big Sur beta and you’re using the Finder and not Terminal, the path is ~/Library/Containers/Safari/Data/Library/Preferences/.²

No matter how you get to that folder, open the com.apple.Safari.plist file in it using your favorite text editor—I’d, naturally, recommend BBEdit, but TextEdit should work too.

Scroll down or search the file to find the phrase IncludeDevelopMenu—this isn’t the key that you want to edit, but it’s handy to keep things organized. Above that entry (which should start with <key>), paste the following two lines:

<key>IncludeInternalDebugMenu</key>
<true/>

Save the file, reboot Safari, and voilà, the Debug menu should appear, allowing you to once again set your tab behavior to that which is undeniably correct. Happy tabbing!

[Dan Moren is the East Coast Bureau Chief of Six Colors. You can find him on Twitter at @dmoren or reach him by email at dan@sixcolors.com. The latest novel in his Galactic Cold War series of sci-fi space adventures, The Nova Incident, is available now.]

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