Do multiple h1's cause screen readers problems?

Question

When I put a website I am building through a W3C checker it asks me to consider only using h1's as a top level heading and points out a section where I have a h1 inside of a section. It also mentions that screen readers will treat them all as top level elements, however, according to HTML5 specs, sections effectively "reset" the headings so you can start another hierarchy from 1-6 within them.

Should I only be using h2-h6 within sections if we are trying to focus on W3C validation and accessibility? Or is this warning incorrect?

Answer 1

Using h1 everywhere is valid (if sectioning elements are used correctly), but the HTML5 spec encourages authors to use heading elements of the rank corresponding to the section’s nesting (h1-h6).

Why encouraging not to use h1 everywhere, although this can be beneficial? Most likely because not all relevant user agents (like screen readers) support the HTML5 outline algorithm.

So if you want to support screen readers that don’t support HTML5 and/or the outline algorithm, you may want to follow the advice to use heading elements of the appropriate rank.