By Pete Freitag
Safari does in-fact have some handy debugging tools for web developers (DOM Tree, User Agent Spoofing, etc), but they are all hidden and disabled by default.
The easiest way to turn on the debugging menu in safari is by installing Safari Enhancer.
Update: Modern versions of Safari have a debugger builtin which you can access by enabling Show Features for Web Developers in the Advanced tab of the Safari Preferences modal. Once you enable features for web developers a Develop menu will appear.
Make sure you check the box
Debugging Menu, you can see that there are also some other handy features in Safari Enhancer. Click
Apply Lasting Setting when your done.
Safari should reload and you will have a new menu called
Applications / Utilities / Console).