How to Align Text in HTML. In HTML, text is aligned using a property called "text-align" that can have three values: "left," "right," "center" and "justify." When you add this property to an HTML ...

Learn how to optimize your website's image SEO and accessibility with alt text. Discover what alt text is, why it's important for SEO, and how to use it correctly.

The basic editor Tumblr provides for posting, however, does not include a way to change the alignment of text or images, so to center an image you have to edit the post's HTML code manually.

The alt attribute holds a place for alternate text. This is important for accessibiity, or when slow internet might prevent the image from loading.