Twitter allows you to create a profile widget that display your Twitter posts on other websites, such as your Tumblr blog. You will need to configure your widget and copy the widget HTML code on the Twitter website. You can then add the code to your Tumblr’s theme by customizing the theme’s HTML code. You should have a basic understanding of HTML code and layout before you attempt to edit the Tumblr theme’s HTML code.
Get Twitter Widget Code.Log in to your Twitter account, and navigate to the Twitter Widgets page.Click “My Website” from the left menu, then click “Profile Widget.”
Configure your widget by changing the settings for the “Preferences,” “Appearance” and “Dimensions.” This will be different depending on how you want your Twitter widget to appear.
Click the “Finish and Grab Code” button.
Click inside the code text box. Twitter will automatically highlight the code for you.Right-click and select “Copy” from the menu.
Add Widget to Tumblr.Log in to your Tumblr account, and click “Customize” from the right menu. This will take you to your Tumblr blog in customization mode.
Click “Theme” from the top menu, then click “Use Custom HTML.” A text box with the theme code will appear.
This indicates that the code below it will display in your theme’s sidebar. Different themes may have a different name for this class, but it will usually indicate that it is the sidebar.
Right-click under the sidebar tag and select “Paste” from the menu to place the Twitter Widget code in the Tumblr theme.
Click “Update Preview” to see the changes to your theme without making them permanent. This allows you to make tweaks to the layout.
Click “Save + Close” to save the changes. When you view your Tumblr blog, you will now see the Twitter widget in the sidebar.