Text size is affected by multiple factors including browser default styles, styles added by the HTML document, browser settings, and sometimes user style sheets.

How to Change Body Text Font on Tumblr. Tumblr's Customize page can be used to make basic changes to your blog, including title, description and links. While this page enables you to customize ...

Decreasing the Font Size on Facebook. Facebook has no built-in function for changing font sizes permanently. The site's Help Center suggests using your Web browser's zoom feature to make text ...