Identical H1 tags on multiple pages occur frequently. This is because CMS systems such as WordPress and co. are often used with design templates. Many of these templates define the logo in the menu as H1. As a result, the H1 is identical on all pages.
Regardless of this, it is of course possible to use identical H1 tags on multiple pages. However, the question is: Is there an advantage in doing so? If there are multiple pages for one main keyword, the risk of keyword cannibalisation arises. Using identical and actually matching H1 tags on multiple pages is therefore most likely the result of a problematic keyword strategy.
You should not use unsuitable H1 tags in the first place. A recommendable use on multiple pages does not seem very likely, at least apart from the logo design question. So the answer is: You can, but you probably shouldn’t.
A missing H1 heading is a missed opportunity because an H1 has clear symbolic power for Google and other search engines. It clearly indicates what your website is about and what the main topic of the page is. If chosen wisely, it supports the indexing of the website for its important keywords. Not using an H1 can have a negative impact on the rankings of the most important keywords, because an important indication is missing.
However, a missing H1 is not a disaster. Users are not bothered by the lack of a corresponding label and instead are usually only interested in the heading, which is visually distinguished as the headline. They don’t even notice if the “H1” label has been attached to it “internally”.
And search engines? They are now more advanced in their development. The keywords in the H1 are just one of dozens of ranking factors. Anyone who still assumes that they decide the fate of a website underestimates the complexity of content analysis.
Empty H1 usually have a very simple reason: On templates for CMSs like WordPress or Joomla, the logo is often marked as H1. If there is only an image and no text here, the H1 is “empty”. In principle, however, this is not a serious problem. Since it is quite possible to use more than one H1, the most important heading on the subpages can also be marked as H1.
Having more than one H1 heading on one page is not allowed according to the HTML5.1 definition, but negative consequences are unlikely. For a long time, the rule was that there should never be more than one H1. John Mueller, Google’s Senior Webmaster Trends Analyst and a spokesperson for the company, pointed out in a Google Webmaster Hangout back in 2017 that, contrary to popular belief, this was not a problem.
He said it is normal for there to be different areas on a website (the popular one-pagers are a good example of this), which can of course be marked with their own H1. The “only one H1 per page” rule persists, but it is outdated. If the distribution makes sense, multiple H1s have no negative consequences.
