ℹ️ As of June 11, 2026, Studio.Design's published site infrastructure has been updated to a setup that returns fully rendered HTML from the server.
In this article, we refer to the updated standard published site infrastructure as the "new infrastructure," and the standard published site infrastructure used before June 11, 2026 as the "old infrastructure."
For details about Studio.Design's published site infrastructure, see Studio.Design's published site infrastructure.
H tags aren't detected because SEO checker tools don't support the old infrastructure (SPA). The h tags themselves are correctly output on your published site, and this doesn't affect how Google evaluates your site in search. If you want them to be detected, switching to the new infrastructure will resolve the issue.
Why h tags aren't detected
This happens because SEO checker tools don't support how the old infrastructure (SPA) displays content.
Studio.Design's old infrastructure displays published sites using SPA (Single Page Application). With SPA, the initial HTML returned doesn't include the content—instead, JavaScript renders it in the browser. SEO tools that don't run JavaScript (such as SEO Cheki and Ubersuggest) can't read the h tags.
Impact on Google Search
Even if h tags aren't detected by these tools, it doesn't affect Google's evaluation of your site.
Google's crawler runs JavaScript and can recognize content in SPAs. In fact, sites built and published with Studio.Design are correctly indexed in search results.
You can confirm that your h tags are reflected in the HTML by opening Chrome's Developer Tools on your published site.
Tip:
Switching to the new infrastructure (SSR) lets SEO tools detect h tags as well. The new infrastructure returns fully rendered HTML from the server, so even SEO tools that don't run JavaScript can read the HTML, including h tags.
For instructions on how to switch, see Switching your published site from the old infrastructure to the new infrastructure.
Improving your SEO
SEO involves many factors beyond just setting h tags, and it's important to consider them together.
Check out the related articles below for more on improving your SEO.