Site navigation is one of those areas that has many facets of importance when it comes to both SEO and usability. A good site navigation makes it easier for Google to crawl and index a site, but it also needs to be usable for visitors to the site, since many use that same navigation to find their way around a site.
An interesting question came up about if Google views different types of site navigation as better for ranking or SEO.
The question: With regards to main navigation, are some types better than others or does it really not matter as long as it’s usable?
Here is what John Mueller from Google responded.
As far as I’ve seen, it doesn’t matter. So looking back at the number of sites I’ve looked at from the help forums to larger sites that have come to us, I don’t think I’ve ever run across an issue where the normal site navigation has caused any kind of SEO problems.
Kind of outside of the general issue of you have a terrible URL structure and we can’t crawl you without finding five bazillion URLs. But that’s kind of the normal navigation structure, if you have a kind of a mega menu style, or you have dropdowns, those kinds of things.
That’s really more more up to you, and more usability than SEO.
There are some points that Mueller doesn’t mention. You do need to make sure it is crawlable – but that is easy to check with a Google Fetch and Render in Search Console, so that Google can understand the navigation, since it can help Google crawl and understand the site’s hierarchy and pages/sections that are likely more important.
There is also potential issues with Google’s upcoming mobile first indexing where sites have a more involved navigational structure on desktop with a “lighter” version on mobile. Mueller has commented on that previously here.
Another site navigation SEO tactic some sites utilize is nofollow on navigation, either for some navigational links or all of them, which is specific for crawl budget purposes. To this is another situation where the use of nofollow on navigation could have an impact on the site’s overall SEO.