How to Use HTML in WordPress Text Widget

1. Visit yoursite.com/wp-admin and log into your WordPress dashboard. Click 'Appearance' and then 'Widgets' in the left-hand menu. On the right-hand side of the screen are your website's sidebars and other widget-capable areas, named things like 'Sidebar' or 'Footer Widget Section.' These names usually describe the section of the page they effect. Click on the one you want to work with to expand it.
2. Find the 'Text' widget in the middle of the 'Widgets' page and drag and drop it into the sidebar of your choosing. You can add as many 'Text' widgets to as many sidebars as you like.

3. Fill in the title if you wish a title to appear over the widget's content when you visit the site. Leave it blank if you do not want a title. Paste your HTML code into the bottom input field of the 'Text' widget. Check that the checkbox at the bottom is not checked, because automatic paragraphs will interfere with your HTML code. Click the 'Save' button to update the widget with your new content.