I'm thinking about using rel=canonical for search filter URLs. If I use this tag, my web pages with parameters never get ranked. If I do not use this tag, it may cause duplicate content problems.


This page is about CCTV companies. .this page optimized for general keywords like "CCTV" or "Buy CCTV".

I also want to filter the content with properties like "Network Type" or "Brand Name". Then the URL, Title and Meta description change and content is more closely related to visitors interest:


This page is optimized for long tail and more closing keywords like: "samsung cctv types" or "chines cctv models".

If I use rel=canonical for second (filtered) URL, the second URL won't rank. Some long tail keywords will be lost.

If I do not use canonical tag, problem is duplicate content. Some content on the filtered URL would duplicate the first (main) URL.

4 Answers 4


If the page changes due to filters are significant enough, it is a new page. There is no reason to think otherwise. It is not necessary to use a canonical tag if the filters change the page enough not to get into trouble. You need to check this of course. I used to use this method for several pages on my site that could potentially create 250,000 or so pages. I opted to remove them due to low value, but I was using it primarily for navigation. In your case, you are using the same method for content. It should work as long as the filters change the page enough to be unique and do not create low value content or pages with too little content.

  • my website is web 2 and products added by users.i can not detect significant enough changes for each category.maybe one of filters has 80% duplicate content.and on of filters has significant enough changes. Apr 16, 2015 at 18:13
  • @Mohsen.Unlimited I understand where you are coming from. I would think 80% may not be duplicate content- however, it might be best if others comment on this. It is possible that you would be right on the edge with 80%. Not sure.
    – closetnoc
    Apr 16, 2015 at 18:27
  • this is my comment.i could not send completely in previous comment: i can not detect significant enough changes for each category.maybe one of filters has 80% duplicate content.and one of filters has significant enough changes. also maybe a filter , has not significant enough relative to another filter.yes.this is unclear.but i am going to do your method Apr 16, 2015 at 19:17

Having some duplicate content within your site is not a problem. If a page has too much duplicate content, Google may choose not to index it. If there is some duplicate content, Google may choose not to include the duplicated sections of the page in the index for that page. Google won't penalize your entire site for duplicating content between pages. See What is duplicate content and how can I avoid being penalized for it on my site?

Your strategy of changing the titles and meta descriptions of your pages is a good one. Google is much less likely to drop a page from the index when the title and meta description are unique.

With product filters you also need to be careful not to allow Googlebot to crawl too much. If you have ten filters with four options each that can be applied on a page there are 10^4 or 1,048,576 possible different pages that Googlebot could crawl. As a general rule never let Googlebot crawl a page with more than one filter (or possibly two for popular combinations) applied at the same time.


Categorize everything and make a hiearchy (tree) to represent each product.

You already have your domain. Here I'm gonna call it example.com. The next text that should follow is any major category where many of your products fall under.

So if you ran a store, and it only sold a wide variety of items but a third are premium items and a third are standard items and a third are discounted items, then the first text could be one of those three things I mentioned and you can begin your tree like this:


Do keep in mind that each URL needs to have unique content. For example, http://example.com can talk about a few best sellers and why they sell well.

This URL:


could present information about what it means when products are premium and then example products can be displayed.

Then you can keep going deeper. So if you sell premium forks, premium plates, discounted cars, discounted apples, standard paper, and a standard computer, then you can have URL's like this:


Then for each additional URL I added, you talk about each item and why its in that category. For example, You can talk about forks and why they are premium.

As a bonus, you can define a naming convention so that navigation keywords don't follow it. Take a look here:


As you can see, I added a colon in the name and defined a rule where an item category name or item name cannot contain a colon because if it does, then navigation could be messed up. As for the above URL's you could redirect




unless you're writing unique content for each page (meaning where the first URL is a nice intro and the pages list the content)

Nevertheless, make sure the content between each page is unique enough and use unique titles and unique meta descriptions and try to have 300 words per page.

Once you get into a habit of categorizing then you should never run into a duplicate issue again.

  • Thanks for your useful answer.Problem is in each url.Url x.com/standard has many parameters.for example :x.com/standard?color=red&type=network . I could not understand how must to do for this type of pages. May 17, 2015 at 5:28

Ok, then I'll add to my answer. Categorize more.

So you could have standard red tv's and premium blue monitors and premium blue tv's.

Have URL's like this:


Then in the first URL, list some things that are standard then explain why they're standard. Then for the next URL, list some things that are standard and red. Do the same with the 4th and 5th urls but think premium. The 3rd and 6th url are product pages.

I think in your URL, network may be a feature that applies to certain items, so anything like that can be mentioned on the actual product page itself.

  • Problem is another thing.You just write optimized urls.Problem is not choosing query string or rewrited urls.Also maybe i have many parameters.For example color=red&type=network&size=20&apply=home. I can not rewrite url for all parameters.Another thing is parent group.Any content in closer and deeper urls, exist in parent url.So , duplicate content problem still is a question. May 18, 2015 at 8:02
  • Then the least you want to do is choose a unique title, unique meta description and unique content for every page. Avoid importing 3rd party templates that contain text as much as you can as that can raise the chances of content being duplicated. May 18, 2015 at 19:02

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