The page under examination has a title that only appears once JavaScript has been executed, meaning it is absent from the page's initial raw HTML response.
Why is this important?
As per Google's documentation, the use of JavaScript to manipulate a page's title is permissible:
Nonetheless, relying on JavaScript to deliver critical content to search engines is not the most efficient approach.
Rendering web pages consumes a lot of resources and is slower than processing the raw HTML. Google crawls in two phases: the initial glance at the HTML response, followed by page rendering for a second evaluation. The index is then updated based on the rendered content.
This means URLs often join the index based on the initial look, and it could be a while before the second rendering-based look occurs.
Thus, it's crucial for the HTML response to feature all essential elements, like the page title, ready for indexing. Missing titles can lead to Google creating its own or delaying indexing until after rendering.
What does the Optimization check?
This Optimization is activated for any internal URL with a page title in the rendered HTML absent from the response HTML.
Examples that trigger this Optimization
This Optimization will be set off by any URL with a <title> tag in the <head> section of the rendered HTML that's missing from the response HTML.
An example of response HTML missing the title:
<!doctype html><html lang="en"><head> <meta name="robots" content="index,follow"> ...</head><body>...</body></html>
While the corresponding rendered HTML includes a title:
<!doctype html><html lang="en"><head> <title>A Sample Page Title</title> <meta name="robots" content="index,follow"> ...</head><body>...</body></html>
How do you resolve this issue?
Relying solely on JavaScript for key on-page content can result in wrongful indexing or indexation delays. It's especially critical for Google to access the page title during its first crawl.
To fix this, teams need to ensure the page title is in the response HTML, unaltered during rendering by JavaScript.