It is important for SEO to know when to use categories and when to use filters to sub-divide the pages of your website because this can have a profound effect on your SERPs rankings. But first you need to know the difference between the two?
Categories are the most natural way to divide your site into pages and are often cleaner and easier to crawl by search engine spiders.
For example, supposing you are developing an e-site for a furniture store, you would first want to designate an individual page to each specific item of furniture – such as beds, dining room sets, couches and arm chairs, dressers.
Then within each page you might want to break it down further into subcategories – so the beds page could be further divided into single beds, double beds, queen size beds, children’s beds, bunk beds, etc.
Your URL for the general bed page would then read: “http://www.furniturestore/beds.html” and you would have individual URLs for each sub-category that would read, for example: “http://www.furniturestore/beds/bunkbeds” or “http://www.furniturestore/beds/singlebeds”, etc.
Once you have your categories established, then come the filters. Filters are ways of distinguishing items within the same category or sub-category – so to continue the example above, you could filter bunk beds according to price points, or material, or color, etc.
In the case of filters, your URLs will probably include a question mark, for example “http://www.furniturestore/beds/bunkbeds.html?style=material=wood”
You can sometimes tell you are dealing with a filter when you see a question mark (?) in the URL.
Google and other search engines tend to recognize and rank categories above filters because their URLs are cleaner and more directly obvious than filter URLs. Just as the “?” in the URL filter leapt to your attention, so too it appears to Google.
Think about the website you are creating and try to focus on the words that you think will attract the highest volume of searches. One excellent tool for fine-tuning this is Google Keyword Plannerwhich you can use to create natural categories and mapping for your site.
The great asset with this tool is that you can see for yourself the number of monthly searches for each category heading you might consider, and so choose the one that seems most appropriate for your client is offering.
Another method to decide on category headings is to use specific metrics for your site.
Try to limit the number of categories on your site as too many can be overwhelming both to viewers who may get confused when confronted with too much choice.
As a rule of thumb, you don’t want to have more than four layers of categories (ie, one main category and then a maximum of three sub categories). Any more than this and your pages may not be properly crawled by the search engines.
If you still need to further sub-divide you could then move on to using filters.
There are not hard and fast rules but some of the simplest are often the best – eg color, size, price, etc. The advantage of filters is that they both streamline the amount of information that will be returned to your viewers and can reveal items that may not be searched for very often.
In the end, for effective SEO it is important to know how to use categories and filters effectively so that your site users are able to access the information they are looking for and so that Google, Bing and other search engines can index your website in an efficient and operative way.