Safari has an interesting feature. For every website you visit Safari will take a screen shot of the webpage. These screen shots are used to populate the topsides list, and the cover flow images in your history and bookmarks menu. It is also used to generate the image you seen when you use the trackpad gesture to view the previous page. It is useful however if you are a privacy nut, or don’t want them to be stored, this post is going to show you how to view them, delete them and stop Safari from generating them.
The Screen Shots Location
For every webpage you visit a screen shot is generated. To find theses image open up Safari and navigate to [User]/Library/Caches/com.apple.safari/Webpage Previews. If you can’t find the Library menu in your user folder, within Finder hold down alt and select library from the Go menu bar option.
Within this folder you will see all of the generated screenshots. It is quite interesting going backwards in time seeing all of the pages you have visited.
Deleting The Images
If you want to remove the images, simply select them all and drag them into the Trash. When you empty the trash they will be gone for ever.
If you don’t want to navigate to this in-depth folder every time, you can use the built in option within Safari. From the menu bar, select Safari then Reset Safari. From the option, ensure the option “Remove all webpage preview images” is selected and hit the reset hit. This will delete the images for you.
Stopping Safari From Generating ScreenShots
If you want Safari to never generate the screen shot images you can do this with a Terminal command. Open Applications > Utilities > Terminal. Then type the following into the Terminal window.
defaults write com.apple.Safari DebugSnapshotsUpdatePolicy -int 2
When you restart Safari, it will never generate any screen shot images. If you monitor the folder it will not generate any new images. The side effect of this is top site, cover flow in bookmarks and history, plus the effect when you gesture to a previous page will stop working.
If you want to re-enable this option enter the following into Terminal.
defaults write com.apple.Safari DebugSnapshotsUpdatePolicy -int 1
After restarting Safari screenshots will be generated.
Its only a minor feature of Safari however one that is rather interesting. I quite like viewing really old images to see what I have been looking at. However, it could be a privacy risk, especially if it records something like your financial data. Credit for this tip goes to reddit.