With version 6 of Safari Apple changed the Delete/Backspace key so that it no longer takes the user back in history to the prior page. While many users are very happy with this change, others are missing one of their favorite shortcuts.
One of the first things many users of notice when updating to Mountain Lion is that the Delete/Backspace key no longer takes the user back to a previous page in Safari. This was removed because frequently users filling out forms would be mistakenly navigate away when trying to edit information in a form. It only losing a ton of data after filling out a long form to really dislike this shortcut.
However, like many other shortcuts, many mac users do not mind this risk and are upset that one of their common shortcuts has been removed in Safari 6. Several options exist for returning the prior functionality.
Use the new shortcuts
Learning Apple’s new shortcut is probably the safest and easiest method. While holding down the command key, the left and right arrows now move back and forward through history respectively. Therefore, to replicate the prior Delete/Backspace shortcut, just hold down the command key + left arrow at the same time.
Additionally, the swipe commands available on a track pad or magic mouse will easily navigate backwards and forwards through your history. Swiping left to right with two fingers will navigate backwards to the last page that you visited.
By using this terminal hack, you can force your delete/backspace key to work like prior versions of Safari. Open up terminal, paste the following code all on one line, and press the enter key. Although the text is too long to be displayed correctly here, all the code below should be pasted as one line in your terminal.
defaults write com.apple.Safari com.apple.Safari.ContentPageGroupIdentifier.WebKit2BackspaceKeyNavigationEnabled -bool YES
If you want to reverse the changes again, you would use the same command but change the “YES” to “NO” instead. After running these terminal commands, you will need to quit and restart Safari to see your changes.