Mac file sharing not working? Easy illustrated guide to setup

If you have work colleagues, a partner or friends with Apple Macs, you will probably need to share files with them at some point. Let’s see how the built-in file sharing in macOS works.

In a recent article, How to sync files between Macs, I showed one method of sharing files and folders between Macs. There are other ways and here I look at the file sharing capabilities of macOS. This is limited to Macs on the same network at work or at home. It does not work over the internet. Sharing files over a network is very common and often needed, but what if it is not working?

The problem could be very simple and it may be a settings problem. If the settings are not right or if you miss one, file sharing might not work. You must configure it correctly.

I have Macs, a MacBook Pro and a MacBook Air and accounts on both. Sharing with yourself is a no-brainer. Just put your files in iCloud and they are accessible everywhere you sign in – Macs, iPhones and iPads.

The difficulty comes when you want to share files with other people, so let’s see how to connect a MacBook Pro and MacBook Air with different users to share files.

Enable File Sharing

Enable file sharing on the Apple Mac in System Preferences

File sharing must be enabled on the computer that wants to share files and it will not appear on the network until this is done. Go to System Preferences and click Sharing. Tick the checkbox next to File Sharing.

There is a list of shared folders in the middle and by default, macOS creates a folder called Public in every user’s home folder.

This is not the only folder that can be shared and the plus button below the Shared Folders list enables you to share other folders on the Mac. Whether the default or another folder is shared makes no difference and the following steps apply.

Other Macs on the network will now be able to see this Mac now that file sharing is enabled. If you don’t see the shared Mac, log off and log back in on both Macs.

Enable the Guest User

Enable the guest account in System Preferences on the Apple Mac

Seeing a Mac on the network does not mean you are able to connect to it and access shared folders and files. Not yet anyway.

Open System Preferences and click Users & Groups. Click the padlock in the bottom left corner and enter your admin password so you can make changes.

Select Guest User on the left and on the right, tick the checkbox Allow guest users to connect to shared folders. This enables others to both see the Mac and connect to it. It is not necessary to allow guests to log into the computer.

Log off and log back in on both Macs after making this change.

Browse the network

Browse the network for Macs using Finder in macOS

Open a Finder window and look in the Locations section of the sidebar. (You might need to open Finder preferences and tick all the options to add everything to the sidebar.)

Select Network and there is a shared Mac – the MacBook Air in the screenshot has file sharing and guest users enabled. Only one folder has been shared, so double click the Public Folder to open it.

File sharing permission problems

Problems sharing files in macOS on the Apple Mac

Here the Public folder on another Mac has been opened in Finder. A file has been dragged to it and dropped. It does not copy to the folder and a message appears saying “The operation can’t be completed because you don’t have permission to modify some items.

  • You can connect to another Mac’s public folder
  • You can see files and folders in the Public folder
  • You cannot access files in the Public folder
  • You cannot drag files to the Public folder

Use the Drop Box folder

Use the Drop Box to share files on the Apple Mac

Every user account has a Public folder and inside that folder is a subfolder called Drop Box (not to be confused with Dropbox online storage). You can drag files from the desktop or from a Finder window and drop them on the Drop Box folder on the networked computer. This enables the person on the other Mac to access files.

Apple Mac file sharing permission problems

This is not really file sharing and it is more like sending the person a file. You cannot access the Drop Box folder and you cannot access the files you send to them. It is useful if you want to give someone a file and don’t want to use AirDrop, but it is useless if you want to work on files with other people.

Set shared folder permissions

Set permissions for file sharing on the Apple Mac

Return to System Preferences and open Sharing again. Select the shared folder in the list and on the right in the Users list, select each item and set the permissions to Read & Write.

Log off and log back in on both Macs after making this change.

Any other Mac that connects to this Mac can:

  • See the Mac on the network
  • Connect to the Mac
  • Open the shared Public folder on the Mac
  • Copy files to and from the Public folder

Mac file sharing permissions

File permissions problems in macOS on the Apple Mac

You can still have problems opening and editing files in the shared Public folder on another Mac on the network. When a file is created on a Mac, a user ‘owns’ it and can open, edit and delete it. Other users may only be able to see it, but they don’t have permission to open, edit or delete it.

Set file permissions in macOS on the Apple Mac

To enable other people to access a file in the Shared public folder, the owner must change the permissions. Select the file and press Cmd+I to view the file info panel. Right down at the bottom, select each name and set the Privilege to Read & Write.

You now have a shared Public folder that can be accessed by other Macs on the network and files that can be opened and edit by anyone. This is great for working on shared projects and resources.