H1 tag checker
The H1 is the main heading of a page and tells people and search engines what the page is about. Marlo flags pages with no H1 and pages with more than one. Paste your URL to check your homepage.
Free. No signup. Open source.
What Marlo checks
- Exactly one <h1> on the page
- That it is not empty
- Headings that do not skip levels, such as h2 straight to h4
How to fix your H1
<h1>Your page topic in a few words</h1>
<h2>A section</h2>
<h3>A detail inside the section</h3>- Use one <h1> for the main topic of the page.
- Make other headings <h2> and below, in order.
- If a logo or banner uses an <h1>, change it to a <div> or <p> and keep the real title as the H1.
How common is it?
In Marlo's own audits of 365 homepages (as of 26 October 2026), "No H1 tag found" was found on 67 sites, 27% of the 251 sites with two or more findings. That group is filtered and the sites came from a few directories, so treat it as a snapshot, not a base rate for the web. See the full numbers.
Questions
Can a page have more than one H1?
HTML allows it, and a page can still work. Marlo flags it because one clear main heading is simpler for readers and search engines.
Should the H1 match the title tag?
They do not have to match, but they should describe the same topic.
How do I check my H1, H2 and other header tags online?
Paste your page address above. Marlo reports whether there is one H1 and whether the heading order skips a level, such as h2 straight to h4.
What is a header tag checker?
It reads the heading tags (h1 to h6) on a page and flags problems with their count and order. Marlo does this as part of the same audit.
