How important is the HTML structure for on-page/on-site SEO?

[Saugar]

To be more specific, say a page layout has Header, Body, Left Sidebar, Footer sections. Which layout from the following options is more SEO-friendly?

1. Header > Body > Right Sidebar > Footer
2. Body > Header > Right Sidebar > Footer

Does it make a big difference to code HTML so that the the copy of the body appears in front of all other sections when spiders crawl a website? Is it worth taking extra steps to make this happen?

I am asking this question because our site has a header navigation with a lot of dropdown menus. So I assume that this is "noise" for spiders as it pushes the main content of the page down.

Please bear in mind that the question is more geared towards how search engine see the page rather than how it appears to the end user as layout can be controlled by CSS.This question also assumes that all other on-site SEO best practices are followed for both options.

[TammyWood]

I agree with the other answers, but believe 100% your header should be above body content. The way I explain it to my clients is the header is a promise of what is to come. You wouldn't pick up a book without reading the title would you? Or know if it is in your own language?

The header is also the position to tell the SERP's what your entire site is about, look this site is about "such and such" with the "author tag so and so", written to answer "these questions" and you will find ALL that and more in the content.

Body above the header was a trick used years ago in SEO to force feed our intentions on the search engine, now we just politely introduce our page and let them browse the content.

[TommyTan]

Hi,

As irving mentioned in his answer, Google does crawl the whole page.  However, from a HTML5 course I took, Google reads the HTML from top to bottom.  Meaning if you have 1. Head > Body >Right Sidebar > Footer, Google will read your head first, then the body, then the right side bar and finally footer.  If you have 2. Body > Header > Right Sidebar > Footer, they will read Header first.  You get the point.

Therefore, it is suggested to have your more important content on the top of the HTML.  But overall, Google will crawl the whole page.

[irvingw]

Google reads the whole page, but it is said to put your content as high up in the code as possible. So if your header is a huge chunk of code, then putting the body above it sounds like a good idea.