Stopping your Tumblr sidebar from scrolling requires a small edit to your blog theme's HTML code. Because every Tumblr theme is different, the steps for making this change vary from one theme to another. Although it may take a little trial and error, you should be able to make the change yourself without any advanced knowledge of HTML coding.

Step 1

Click "Customize" on your dashboard, and then click "Edit HTML" on the Customize page to view your theme's HTML coding.

Step 2

Press "Ctrl-F" to bring up the search tool, and then enter "