There are many ways or apps to transfer data from your Android device to Mac or the other way around. CX File Explorer for Android is one of them. This free app has made the wireless connection and file transfer between mobile phones and computers ready easy. It can turn your Android smartphone into an FTP server so you can connect your Mac to Android FTP server to copy files between them. You can also enable the file sharing on Mac, then connect to your Mac using the app from your cell phone.

Enable file sharing on Mac
On the Mac, click the Apple menu from the top menu bar, then go to System Preferences > Sharing. Click to select the File Sharing checkbox to enable file sharing on Mac.
To select a folder on your Mac to share, click the Add button at the bottom of the Shared Folders list, find the folder and add it to the Shared Folders list.

Access Mac shared folders from Android
Open Cx File Explorer on your Android phone.

Switch from the Local to Network tab.

Tap New location > Remote, you will see options for connecting to devices remotely, such as Local Network, SMB, FTP, SFTP, WebDAV, etc.

Choose Local Network. Then the file explorer app on your Android phone will scan your local network for new devices. Your Mac should appear here. If not, make sure to connect both your phone and computer to the same Wi-Fi network.

Tap on your Mac name here. Then input the username and password which you use to log onto the Mac. Press on OK.

After that you can browser, open, play, copy & paste files stored in the shared folders on your Mac using the CX file explorer on your Android phone.

Other than setting up the file sharing server on Mac, you can also use the above file explorer app to create an FTP server on Android phone for file sharing between the mobile and computer.
Create FTP server on Android
Launch the file explorer app on your Android device, switch from the Local to the Network tab.

Then tap on Access from Network > Start Service. You will then get the FTP address(server IP and port number), username and password, see screenshot below.

Connect Mac to Android FTP server
On the Mac, click on the Finder in the Dock. Navigate to the Go menu, then choose Connect to Server. Type the address of the FTP server with port number into the text box, such as ftp://192.168.50.75:8791. Press Connect.

Click another Connect button to continue. You will be requested to type in your username and password for the FTP server.
- Connect As: Registered User
- Name: pc
- Password: the random or predefined password in CX file explorer.
Finally hit the Connect button to establish the connection between your phone and computer.