Apple - How to disable face detection in Photos for OS X

Apparently you can stop face recognition by quitting iPhotos, opening a terminal and typing the following (and press enter):

defaults write com.apple.iPhoto PKFaceDetectionEnabled 0

I guess you'll then need to manually delete all the faces it's recognised thus far.

As for the new "Photos" app, I don't think you can disable the face detection.

Unfortunately, you can only side-step the issue by clicking the Albums tab > Faces, and select each found face & delete it. You cannot bulk select, so this must be done manually for each face.

You should log an enhancement request (or three) at the Photos Feedback page.

Many people say it is not possible to disable that feature. But there might be some workarounds depending on your needs.

If you (and other users of the computer) do not want that feature, you might want to forcibly stop the program that performs the face detection/photo analysis. The process (or program) responsible for the analysis is called photoanalysisd. you can be a bit bold about it and try to prevent the process from running altogether.

Forcibly stopping the program performing the analysis (2 alternative solutions)

Either: (A) Using an app to forcibly pause the process that performs the analysis

As someone said here you can use an external app to pause the process before it goes nuts and makes your computer heat up.

Or: (B) Forcibly disabling the process for the whole computer

You could go for completely preventing the photoanalysisd process from ever starting up by entering a command in Terminal. The command requires admin privileges and that SIP be disabled temporarily, otherwise you would get a permission denied error.

So you can enter the command in the Terminal of the Recovery Mode (booting with Cmd (⌘) – Option (⌥) – R) or from your user session while SIP is disabled (but do not forget to enable it again afterwards). In a Terminal, enter the following command

sudo chmod -x /System/Library/PrivateFrameworks/PhotoAnalysis.framework/Versions/Current/Support/photoanalysisd

If you are running this in Recovery Mode, you might want to disable-reenable SIP all at once with the following:

csrutil disable
sudo chmod -x /System/Library/PrivateFrameworks/PhotoAnalysis.framework/Versions/Current/Support/photoanalysisd
csrutil enable

Basically, it changes the permissions of the program file and forbids anyone from running it. This way, the system will not be able to start it and it won't be a burden for your CPU anymore.

PS: If you update to a newer version of MacOS, you will need to re-do this B) step, since the permissions will be restored.
PSS: If you ever want to enable it again, you might have lost track of this page... so put a note about it somewhere. At least, know that upgrading to the newest would reset.
PSSS: Note that preventing the process from running might have side effects (even though I do not see any after few years).

Restoring the functionality (if used option B)

You can always restore the permissions and everything would be back to normal with these commands run in Recovery Mode. Note the +x instead of the -x.

csrutil disable
sudo chmod +x /System/Library/PrivateFrameworks/PhotoAnalysis.framework/Versions/Current/Support/photoanalysisd
csrutil enable