Content duplication is a problem that many websites face. When we find duplicate content on our website, should we use a 301 or a Canonical?

1. What is Canonical Tag?

Canonial tag is added to the head section of the website, and the writing is:

<link rel=”canonical” href=”https://domainname.com/dress/pink-dress” />

Which pages are processed with Canonical Tags?

Canonical Tags are suitable for duplicate pages that need to be retained or duplicate pages that are automatically generated by the CMS system. Canonical Tag is recommended in the following two situations:

1. Online store website

The same product on the website of the online store often comes in different colors or different sizes. If a piece of clothing has red, yellow, orange, green, blue, indigo, and purple, then the product will have 7 pages of different colors but the same other data, and these pages are all the pages that you want to show people. When Google crawls these pages, it will determine that these 7 pages are duplicates, and duplicate content is not valuable to Google. At this time, we can add a Canonical Tag to these 7 pages to designate one of the pages as the main page, so that Google can identify the relationship between the seven duplicate pages.

2. Forum

The forum system also often has duplicate pages. When we post on a forum, several identical pages are generated (for example, the posting URL of a forum usually has a viewthread, achiver or thread), and many times we don’t even know how many URLs a post will generate. At this point, we don’t care about how many unknown URLs a post will generate. We only need to add the Canonical Tag to the posts in the backend of the website, so that several pages of the same post will be added with the same Canonical Tag at the same time, pointing to the page we specify.

For example, if you add three identical pages, this is telling search engines that you want the https://www.example.com/viewthread.php?tid=29950287 version of the URL to appear in the search results.

Part 2: What is 301 Redirect?

A 301 Redirect is a way to permanently transfer URLs, usually in a .htaccess file. The characteristic of this method of processing is a “perpetual” transfer, where “permanent” means that the domain name is for the duration of your purchase. When the website does a 301, it will automatically jump to the new page when it opens the original page. The corresponding “temporary” transfer method is Redirect 302. We usually use it when the site is in the middle of a temporary adjustment. And we often use Redirect 301 in our SEO optimization. 301 is written as follows:

Which pages should be processed with a 301?

The 301 is suitable for disposal of waste pages. Since these pages may have already been indexed by search engines, if they are deleted directly, it will be detrimental to the SEO of the website. Especially when we need to scrap a large number of pages at once, it will lead to the shrinking of the website structure. If this is the case, it is recommended that these pages be processed in batches. Because a large number of scrapped pages in a short period of time can cause significant fluctuations in website rankings. Moreover, if Redirect 301 is used properly, the discarded web pages can also be “recycled”, which is both “environmentally friendly” and “healthy” for the website!

1. The products of the online store are removed from the shelves

Product pages should not be deleted when our products are removed from the shelves, because these pages are likely to have been indexed by search engines and have a certain authority (Domain Authority). Deleting pages outright wastes the value of those old pages. It is recommended to do Redirect 301 to the corresponding category page or the corresponding new product page of the product.

2. Website Transfer

When the website of domain name A needs to be transferred to domain name B, since the domain name of the website has become a new domain name, after the website transfer is completed, it is recommended to make domain name A 301 to domain name B, so that domain name B can get the authority of the website from domain name A. In addition to helping to rank your B domain, this also saves you from having to start from scratch to promote your website.

In other cases, you can choose either a 301 or a Canonical Tag. For example, when the website has a Blog section or a news update section. For example, when we want to revise some old articles, there is a tricky problem. Since most of the blog page uses the title of the article as the URL, if we want to change the title, we will change the URL of the article and generate a new URL. However, the newly generated page is not weighted. To maintain authority, we can transfer the old page to the new page with a 301. Another option is to keep both the old and new pages of the same article, and add the same Canonical Tag to both pages, telling search engines that the old page is the main page and the new page is a subsidiary page of the old page.

How to Lose Weight and Keep It Off

Finally, a reminder to everyone: 301 rewrites need to be used with caution. After we do 301, if we want to cancel and restore the old URL, even if we can access the old URL normally, it is difficult to restore its weight. This also means that we won’t be able to reinstate the old rankings for keywords that we were ranking for.