With the advent of Safari 4, it seemed that the Debug menu was gone, replaced by the new Develop menu. As it turns out, that’s not the case at all; the Debug menu is still available in Safari 4, but it’s now activated with a new command.
While the debug menu contains a number of commands that are of interest mainly to developers, there are a couple of options that “regular” users may also find interesting. For instance, a Force Repaint command (Shift-Command-R) will redraw the current screen without reloading the site (as would happen with Command-R). This can be very useful if you’re one of those affected by the color fades when scrolling issue that many users have reported.
You can also use the Debug menu to see a full list of keyboard and mouse shortcuts, and to view detailed information on caches; you can even clear various caches from this screen.
If these features sound useful to you, here’s how to enable the Debug menu in Safari 4, thanks to Mac OS X Hints readers chleuasme and Frederico. Quit Safari if it’s running and open Terminal, in Applications -> Utilities. Copy and paste the following command, then press Return:
defaults write com.apple.Safari IncludeInternalDebugMenu 1
When you relaunch Safari, you’ll find a new Debug menu, located to the right of the Help menu. There’s no help available for everything in this menu, though most options are relatively self-explanatory. If you ever tire of the Debug menu, quit Safari, then repeat the above command, but replace the 1 with a 0. Press Return when done, and Safari will no longer have a Debug menu.