问题
are multi-level CSS drop-down menus a big 'no-no' for SEO purposes.
i've read mixed reviews. some say the links in the secondary navigation will not be crawled by search-engine spiders (because they're hidden) while the other say it is part of the HTML, so the spider will 'see' it.
any thoughts? thanks
回答1:
As long as Google doesn't publish their indexing methods, we will never know for sure. But I very much doubt spiders will ignore links because they are in hidden elements. Text and keywords, yes. But links? No. In my experience, all bots are greedy to index as much of the internet as they can.
If you want to make really sure, consider having a second menu that is never hidden, and that shows the current page's "neighbor" links. Maybe have all the links of the current category as small links in the footer. That way, you can be sure every link will be visible on some page that is reachable from a level-1 link from another page.
Actually, I think I have seen sites doing that even though they had drop-down menus. Maybe that's the reason.
回答2:
Depending on the number of links on your page, from what I understand you can be penalized if there are too many. With that in mind, how many are in the content, sidebar, etc. They add up fast - I don't use drop down because I did a test group and a large majority do not like sites with drop down menus.
回答3:
IMHO will be seen. The search engines can not run all the javascript to figure out whether something MAY become visible during normal operations.
回答4:
I've made sites using a drop down menu and they got spidered perfectly fine. As long as the links are in the HTML output (e.g. as an ordinary list) then the links will be seen.
来源：https://stackoverflow.com/questions/2408878/css-drop-down-menu-and-seo