MacOS: Enable Web Inspector In Safari

If you want to view the source code of a web page in Apple Safari for MacOS Sierra, you will have to enable the Web Inspector using these steps.

Safari 10

1. Ensure that “Show Develop menu in menu bar” is enabled under “Safari” > “Preferences” > “Advanced“.
   
2. Now visit any web page and select “Develop” > “Show Web Inspector“.
   
3. The web inspector window will appear.
   

Older versions

1. Open “Applications” > “Utilities“.
2. Launch “Terminal“.
3. Type “defaults write com.apple.Safari WebKitDeveloperExtras -bool true” and press “Enter“.
4. Now you can open a web page in Safari and right-click or hold down your mouse button anywhere on the page until the menu appears.
5. Select “Inspect Element“.