What it is
An H1 is the largest, top-level heading on a page — marked in the page's code as <h1> — and it's meant to be used exactly once per page, as a short summary of what the whole page is about. It typically looks like the biggest, boldest text near the top of a page, though its actual visual size is controlled by design, not by the tag itself.
This check looks for a page having exactly one clear H1, since some pages are missing one entirely, some use several (which dilutes the same signal an H1 is supposed to provide), and some use large-looking text that isn't actually marked as an H1 in the code at all.
Why it matters
Search engines use headings, and the H1 especially, as one of several signals for figuring out a page's core topic — alongside the title tag and the actual body content. A page with no H1 at all, or with the H1 buried under unrelated large text, gives search engines a weaker read on the page's subject than one with a single clear H1 that matches what the page is actually about.
This matters for readers too, independent of any search engine: a clear H1 acts as a quick confirmation, right after clicking a search result or a link, that a visitor landed on the page they expected.
How to fix it
- Check whether the page has an
<h1>tag at all, and if so, how many — you're aiming for exactly one. - Make sure the H1's text clearly summarizes the page's main topic, similar in spirit to the title tag but written for a human reading the page rather than a search result.
- If there are multiple H1s, change all but the most important one to a lower-level heading like
<h2>. - If you're using a website builder, the largest heading style on a page (often literally labeled "Heading 1") usually maps directly to the H1 tag — check that setting on the block containing your main headline.
- Re-run your Launch Readiness check to confirm exactly one H1 is now detected.