Google's John Mueller said again that Google does not index parts of a page - like the header versus the footer versus the main area of the content. Google indexes it all and does not index a piece or part of it. But there is one exception, embedded content on the page, like images, JavaScript embeds and so on.
Google told us this numerous times including back in 2019 when we covered that Google does not index parts of a page independently.
John has clarified this once more on Twitter saying "We don't index pages in parts." He said for some "embedded content, like images, can get indexed separately though" but he added that Google doesn't index all images.
Here is that tweet:
We don't index pages in parts. Embedded content, like images, can get indexed separately though, and we don't index all images. Perhaps that's what you're seeing?
— 🧀 John 🧀 (@JohnMu) November 30, 2021
data-nosnippet is just for snippets, not for indexing.
— 🧀 John 🧀 (@JohnMu) November 30, 2021
There are many SEOs that believe Google indexes parts of pages, Google does not do that.
Forum discussion at Twitter.