• https://plus.google.com/116060438179787966184 salsurra

    Great post about canonical tags. They are so important these days and in some cases, I’m using just canonical tags to move page value instead of doing 301s. There is a strong case showing that it’s better to allow Google to crawl pages on your site, but if the page is duplicate or intended for users, then use the canonical tag to tell Google which page to rank instead of consolidating the pages or trying to setup a 301. 301s are good, but don’t always work for every scenario. Canonical tags are great, but again, don’t work in every scenario.

    Scenario 1 – You have two pages that have similar content, but they are needed for users to help them find what they are looking for or have a specific function on the site. Car sites have a lot of this as their are multiple pages for each trim level, but in fact, most of the data is the same. On these pages, you need to still have each of the trim level pages so that users can find the exact details they are looking for, but if the data is the same on each trim level then this is a good case to use canonical so that Google will only rank one of them and will past the value from the other trim level pages into the one overview page. You make the overview the main source of the data and put a canonical tag on each of the trim level pages. This way you give users what they want, and you give search engines what they want and everyone is happy.

    Scenario 2 – You have two pages with similar content and there is no need to for users to find both. Again, looking at a car site you could find a section for pricing, but there also might be the same pricing data on another page for ‘costs of ownership’ and in these pages are the same details that are on the pricing page. This would be duplicate content that is not really needed for users or engines. In this case, it would be a good idea to pick one of the urls, most likely the stronger one with higher PR, and then setup a 301 to move the other page into the good page. This would reduce the number of duplicate or low quality pages in Google, resulting in higher rankings for those pages and the rest of the site.

    To be clear though, its not good to do both. If you 301 page, then Google will remove it and not crawl it again. This means if you have a special canonical tag on the page it will be ignored because the crawlers won’t even get to it. The other issue is that you can use noindex and canonical at the same time. If you noindex a page with a special canonical tag, then Google will ignore it because the bots are not allowed to crawl it. If you want to have a page with a special canonical tag, you must allow Google to crawl the page and read the canonical tag. They will do the heavy lifting after that and there is no need to use noindex. If you don’t want a page to be in Google, then use noindex tag, robots.txt, or 301 to move it out, but if you want to use canonical tags, then you can’t use any of the above because Googlebot has to crawl the page in order for the canonical to work.