Though you cannot remove the Search field on your Tumblr dashboard, you can delete all Search features from each of your Tumblr blogs. Simply delete the <div> tag that contains the Search feature from the theme HTML code. You can preview your edits as you make the changes in the Preview pane. When the Search option disappears in the preview of your theme, save the theme. You can always revert to the original state of your theme if you want to restore the Search field to your blog.

Remove Search Feature

Step 1

Log in to your Tumblr dashboard, then click the down arrow next to your blog name. Click the blog to modify to open the selected timeline in your dashboard.

Step 2

Click the “Customize” link in the right sidebar menu to open the theme in Edit mode.

Step 3

Click the “Edit HTML” link in the Customize panel to open the HTML editor.

Step 4

Press “Ctrl-F,” then type the phrase “div id=”search” in the Find box. The specified <div> is highlighted in the code. Note that you can search for the <div> tag with or without the outer quotes; just include the inner quotation mark at the beginning of the word "search" in the search phrase.

Step 5

Delete the entire Search <div> including all of its contents and its closing tag </div> located just after the “{lang:All of Tumblr}</label>” statement.

Step 6

Click “Update Preview,” then check the Preview pane to view your changes.

Step 7

Click “Save” to save the code, then click “Exit” to return to your dashboard.

Restore a Theme

Step 1

Log in to your Tumblr dashboard, then open a new browser tab.

Step 2

Open the Theme Recovery tool in the browser (see Resources).

Step 3

Click the “Choose Blog" drop-down list, then click the name of the blog to restore. Click “View Backups” to open the recovery page for the selected blog.

Step 4

Click the “Revert” button next to the version of your theme to restore. The selected theme is instantly restored to your blog.