Google’s Martin Splitt answered a question about how Googlebot responds to a pre-render meta tag that has the value of 404 page not found. It’s a good question because this is the kind of meta tag, a non-standard meta element, isn’t often encountered so it’s good to know what to do when something like this comes up.

The person asking the question wanted to know about how Google might respond to a meta tag in the head section that has the name “prerender-status-code” and a value of “404” which means that the requested page is not found.

The question was asked by a person named Martin and Martin Splitt of Google is the one who answered it.

This is the question :

“Martin is asking: What does Googlebot do when it finds <meta name=”prerender-status-code” content=”404″> ?”

Martin Splitt answered:

“Well Martin, that’s easy to say, Googlebot currently ignores that status code.

I guess this is coming from a single page application that is client-side rendered and you want to avoid soft-404s, in that case consider adding <meta name=”robots” content=”noindex”> or redirect to a page where the server responds with the 404 status code.

For more information on that see our documentation at developers.google.com/search.”

What is Prerender-Status-Code?

The prerender-status-code meta element (sometimes referred to as meta tag) is not an official meta tag and there is no documentation on it at the Worldwide Web Consortium (W3C.org), where the official HTML standards are created.

This is more of a proprietary or non-standard meta element. Non-standard meta elements are are not part of the official W3C HTML specifications. Some non-standard meta elements are browser-specific or are created for specific purposes. Consequently, they may not be supported by different browsers or by search engines. and their behavior may not be consistent across different browsers

The prerender-status-code meta element is an example of a non-standard meta element that also happens to not be supported by Google.

Another non-standard meta element that is not supported by Google is the meta keywords element. There is no reference to it at the W3C.org and it was never a part of the official HTML standards. It was a meta element that was invented by search engines in the 1990s.

The X-UA-Compatible meta element is an example of a browser-specific non-standard meta element that is an outdated meta element that was specific to the old Internet Explorer web browser.

This is an example of the X-UA-Compatible meta element:

<meta http-equiv="X-UA-Compatible" content="IE=edge">

The takeaway from Martin’s answer about the prerender-status-code meta element is that many non-standard meta elements are not supported by Google.

Another takeaway is that not every meta tag is a part of the official HTML standards which can be found at the World Wide Web Consortium website (W3C.org). Those non-official meta elements are called non-standard meta elements.

More information can be found at Google’s support page about supported meta tags, which was last updated on December 1, 2023.

Meta tags and attributes that Google supports

Listen to the Google Office hours video at the 3:46 minute mark:

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