Safari does a great job at making your time on the web easy and simple. It will fill in frequently occurring form information, like your name, address, and email address, so that you don’t have to for every site you visit with a form requesting this information. Fill it out once, then let Safari auto-fill the info the rest of the time. It will also save website user names and passwords. Which, when you think about it, is a great idea for your own personal computer at home, but not so great for a work or shared computer.
Here’s how to disable that.
First, launch Safari from the Applications folder, the Dock, or using some other launching app, like Alfred or Quicksilver. Then, click on the Safari menu and choose Preferences… You can bring the Preferences up with the keyboard shortcut, Command-Comma, as well.
Once the Preferences window is open, click on the Auto-Fill tab at the top of the Preferences window. Now uncheck the User names and passwords checkbox. If you want to clear out the passwords has already stored, click on the Edit button, and then click on the Remove All button at the bottom.
You’ll need to restart Safari at this point, to make sure the changes stay in effect. Now Safari won’t ask you to store passwords and user names, making your Mac just a bit more secure than it already is..