Safari 4.0 and later versions include Built –in tools such as Web Inspector, shown below, to help you prototype, analyze, debug and optimize websites and Web apps.
Safari 5.0 and later has additional tools can use to develop and debug safari extensions.
Enable the Developer Tool in Safari preferences:
1. Select Safari in Menu Bar and Select Preferences……
2. Select Advanced pane of Safari preferences
3.Check the CheckBox of show Develop menu in menu bar.