This translation has not been editorially reviewed yet. The German version is authoritative. Deutsche Fassung →
Content in the first HTML: what arrives with no JavaScript
The check looks at whether the delivered HTML already contains the content, or whether the page arrives empty at first and builds its text only in the browser. The latter is the state in which simple evaluation systems see nothing at all.
- Search engines can execute JavaScript, but do it with a delay and not in every case. Other systems — preview generators in messaging apps, bookmarking services, many answer systems — run none at all.
- The difference rarely stands out in everyday use, because everything works in the browser. It becomes visible when you look at the delivered source code: if there's nothing there but an empty shell, that's the finding.
- The common solution is server-side rendering or pre-generating the pages. Neither changes how the site works to use, only when the content gets created.
FAQ
Doesn't Google index JavaScript pages anyway?
Usually yes, but later, and with more effort. Other systems don't. Anyone who cares about citability in answer systems needs the content in the delivered HTML.
How do I see what's actually delivered?
Via the browser's view-source function — not the developer tools. The latter show the fully built state, not what the server actually sent.