How to Make the Header Picture Smaller in Tumblrby Randall Blackburn
Your Tumblr blog header picture is the image that displays as a banner across the top of your blog. You can edit the size of the header picture in two ways using the Customize tool. In late November 2013, Tumblr updated the Customize tool by adding several new options to the default theme. Using the new options, you can stretch the header image across the top of your blog or disable stretching to make the picture smaller. You can also disable the Sliding Header attribute make the image static and centered on your blog page.
Log in to your Tumblr account, then click the name of the blog to edit in the right panel. Click the “Customize” option under the name of the blog. The selected blog opens for editing with the Customize tool displayed on the left and the Preview window displayed on the right.
Click the “Stretch Header Image” option to turn the toggle switch to the “Off” position.
Click the “Sliding Header” entry to turn the toggle switch to “Off,” if desired.
Click the “Save” icon to save the settings, then click “Exit” to close the Customize tool.
Open your blog in a browser to preview the changes. Note that your changes do not initially display in the Preview window. You must exit out of the editing tool, then refresh the page in the browser to see the changes.
Note that you can make your header image only as small as the actual size of the image. To make the image even smaller, download and open the image in an image editor, like Paint or Gimp. Reduce the size of the image, then re-save the file. Upload the new image by clicking the “Upload” button in the Header section of the Tumblr Customize menu.