I have an eCommerce site that I am working on. The primary way customers find products is by filtering down results with a search menu (options include department, brand, color, size, etc.).
The problem is that the menu creates a lot of duplicate content, which I am afraid will cause problems with search engines like Google and Bing. A product can be found of multiple pages, depending on what combination of filters are used.
My question is, what is the best way to handle the duplicate content?
As far as I can tell, I have a few options: (1) Do nothing and let search engines cache everything; (2) use a canonical link tag in the header so search engines only cache departments; (3) put rel="nofollow" in the filter links-- though, to be honest I'm not sure how that works internally; (4) put noindex in the header of filtered pages.
Any light that can be shed on this would be great.
This is exactly what canonical URLs are for. Choose a primary URL for those pages and make that the canonical URL. This is usually one that isn't found using filters. This way the search engines know to display that URL in the search results. And if they find the filtered pages from incoming links they give credit to the canonical URL which helps its rankings.