Paste your H1-H6 sequence. See structural problems such as skipped levels and multiple H1s.
This tool takes headings line by line in the form H1: and checks the document hierarchy. It looks for exactly one H1, whether the first heading starts at H1, and whether levels advance one step at a time. It flags jumps such as H2 to H4. Each line gets an issue label and the total problem count appears at the end. The goal is a structure that is understandable to both readers and assistive technology.
Copy the page's headings in order from browser developer tools or the CMS editor. Write each line as H1: Title, H2: Section. Plain lines without a level marker are ignored. Fix the structure first, then review the heading text for clarity and keywords. One H1 per page is a practical accessibility and readability choice, not a ranking rule. Also check text that looks large visually but is not marked up as a heading.
The tool checks only the text you paste; it does not crawl the page. It cannot see hidden headings, elements added later by JavaScript or plain text that merely looks like a heading. H1 count alone does not determine ranking. Also verify that mobile and desktop use the same hierarchy. Your input stays in the browser. Last checked: 3 November 2026.
I entered a deliberately broken outline: it jumps from H2 to H4. The tool flagged it as the only issue.
HTML5 allows multiple H1s, but one H1 gives most pages a clearer structure. What matters is that headings reflect the content hierarchy accurately. Build a consistent outline for screen readers and search engines.
A skipped level suggests a missing H3. That is not always a technical error; sometimes it is a design decision. In long content, however, it weakens the reader's mental map and can make screen-reader navigation harder.
A heading should first say what the section covers. Use a keyword if it fits naturally; do not force it. Adding the same term to every heading makes the structure repetitive and hard to read.
The tool reads only lines pasted as H1-H6. Text styled large but marked up as p or div is not a heading. Converting that text to real heading tags helps accessibility.