The URL in question contains an <h1> tag that is missing from the page's initial HTML response but appears after the execution of JavaScript.
Why is this important?
Webpage rendering demands substantial resources and takes considerably longer than simply downloading the source HTML.
Google employs a phased crawling approach: first, they review the HTML response, then they render the page for a second evaluation of the rendered HTML, updating their index accordingly.
Because URLs are first indexed based on the HTML response, there may be a significant delay before the second evaluation occurs, during which the rendered HTML is considered.
Ensuring the HTML response comprises all the vital elements, including an <h1> tag, is crucial for proper indexing from the start.
Without an <h1> in the HTML response, Google might index the page with an incomplete understanding of its relevance, or defer indexing until rendering occurs later.
These scenarios are not ideal, particularly when page content and <h1> tags frequently change, potentially causing out-of-date versions to remain indexed.
What does the Optimization check?
This Optimization triggers for any internal URL that showcases an <h1> tag in the rendered HTML but not in the initial HTML response.
Examples that trigger this Optimization
This Optimization will activate if a URL has an <h1> element in the rendered HTML absent from the response HTML.
Consider this scenario with a response HTML:
<!doctype html><html lang="en"><head> ...</head><body> ...</body></html>
And the corresponding rendered HTML:
<!doctype html><html lang="en"><head> ...</head><body> <h1>The page is excellent</h1> ...</body></html>
How do you resolve this issue?
Depending on JavaScript to generate critical on-page elements may lead to incorrect indexing or delays. Google might not always effectively render or execute JavaScript.
Having <h1> tags available in the initial HTML response is vital for SEO and should be visible to Google upon first inspection.
To remedy this situation, collaborate with the development team to include the <h1> tag in the HTML response, ensuring it remains unaffected by JavaScript during rendering.