Note for zsh users: replace all references to ~/.bash_profile with ~/.zshrc.

Option 1 – Using Homebrew

This is the easiest way and will provide automatic updates.

Install the homebrew package manager

 /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

Option 2 – Manually (just the platform tools)

This is the easiest way to get a manual installation of ADB and Fastboot.

Delete your old installation (optional)
```
 rm -rf ~/.android-sdk-macosx/
```
Navigate to https://developer.android.com/studio/releases/platform-tools.html and click on the SDK Platform-Tools for Mac link.
Go to your Downloads folder
```
 cd ~/Downloads/
```
Unzip the tools you downloaded
```
 unzip platform-tools-latest*.zip 
```

Move them somewhere you won’t accidentally delete them

 mkdir ~/.android-sdk-macosx
 mv platform-tools/ ~/.android-sdk-macosx/platform-tools

Add platform-tools to your path

 echo 'export PATH=$PATH:~/.android-sdk-macosx/platform-tools/' >> ~/.bash_profile

Refresh your bash profile (or restart your terminal app)
```
 source ~/.bash_profile
```
Start using adb
```
 adb devices
```

Delete your old installation (optional)
```
 rm -rf ~/.android-sdk-macosx/
```
Download the Mac SDK Tools from the Android developer site under “Get just the command line tools”. Make sure you save them to your Downloads folder.
Go to your Downloads folder
```
 cd ~/Downloads/
```
Unzip the tools you downloaded
```
 unzip tools_r*-macosx.zip 
```

Move them somewhere you won’t accidentally delete them

 mkdir ~/.android-sdk-macosx
 mv tools/ ~/.android-sdk-macosx/tools

Run the SDK Manager

 sh ~/.android-sdk-macosx/tools/android

Click Install Packages, accept licenses, click Install. Close the SDK Manager window.

Add platform-tools to your path

 echo 'export PATH=$PATH:~/.android-sdk-macosx/platform-tools/' >> ~/.bash_profile

Refresh your bash profile (or restart your terminal app)
```
source ~/.bash_profile
```
Start using adb
```
adb devices
```