See how the headers respond on mobile devices (regardless of the size you select in options).

 

Header 1 (H1) is the Page Title!

Header 2 (H2) is good for sub topics on the page.

Header 3 (H3) is good for clarifying topics under each sub topic for the page.

Header 4 (H4) is rarely used but hey, it’s available.

Header 5 (H5) is kinda used once in awhile?
Header 6 (H6) is so cute!