The HTML element used for the largest heading is h1. In HTML, heading elements run from h1 through h6, with h1 representing the highest or most important heading level and h6 the lowest.
The h1 element usually identifies the main topic of a page or a major document section. Browsers apply a default large, bold style, but CSS controls its visual appearance, so “largest” refers primarily to heading hierarchy rather than an unchangeable font size.
A common mix-up is confusing h1 with head. The head element contains document metadata, such as the title, stylesheets, and scripts, and is not a visible page heading. The header element is a semantic container for introductory content and can include headings, navigation, or logos; it is not itself a heading level.
Modern HTML supports meaningful heading structure, so authors should choose headings for document organization rather than merely making text look large. CSS can enlarge an h2 or shrink an h1 without changing its semantic role.