Duplicate Content was often and long discussed in the field of SEO. Today this topic is still relevant. Among the most frequent questions were and are:
Worried about duplicate content , today, is not worth it, because PS skillfully determine the highest quality page (original) and distinguish it from similar clones. Nevertheless, this question does not leave many webmasters alone. One of the painful questions is the question of the site’s ban due to duplicate content . Blogs, video and audio tutorials, SEO articles, etc., give a lot of tips on how to get rid of duplicate content and ensure your site’s durable existence.
Some advise that it is enough to block duplicates , others - it is better to register redirect , and still others say that it is best to canonize the page . Each of the proposed methods is good, and each has its drawbacks. Let's discuss them in more detail. I note in advance that the purpose of the article is rather to remind of such methods. A detailed analysis of each of them is the topic of individual articles with examples.
Using rules in a robots file. txt - the most common practice among webmasters, because the rules do not require special knowledge of syntax. robots. txt is popular not only among ordinary webmasters, but also among Google experts. You can specify files and / or directories that you index do not need . For example, this may be the results of the CGI-skips, a weather report, etc.
All registered pages in robots. txt will be excluded from the list visited by the robot PS.
Another way to exclude duplicate content is to use service tags Noindex / Follow (example):
. meta name = ”robots” content = ”noindex, follow” /.
Noindex will instruct the robots not to index the page, and Follow will allow the weight to pass to external links. I note that initially the Follow and NoFollow attributes were created to combat SEO spam, so that the target spam pages would not get into the “undeserved” places because of the weight of incoming links on the ball.
What happens to duplicate content when using the 301th redirect? 301th redirect is a great thing in comparison with the first two. 301 redirect is redirecting, which means that the page or the whole site is now at a new address. The PS robot will obediently move to a new page. All the weight, angeling, etc., completely switch to a new url. Nothing is lost and not truncated. That is why domain gluing is so popular. Different webmaster craftsmen earn a lot of ruble on this.
301th redirect can be implemented Web server software (Apache, IIS, etc.) or through server-side programming (PHP, ASP /. Net, ColdFusion, JSP, Perl, etc.).
The canonical link behaves in the same way as the 301th redirect. A page with duplicate content will not be indexed (ideally). Only the page assignments will appear in the index. All pages indicating the canon will be counted as the original.
A simple example. Suppose you have visited an online store and are browsing a page about laptop bags:
http: // www. example. com / travel / luggage / laptop-bags / targus /
At the same time, another customer is looking for a laptop in the store. And he wants to save money and buy it along with the bag. In online stores often use this technique when placing links to related or similar products. So, there is another URL:
http: // www. example. com / electronics / computers / laptops / accessories / laptop-bags / targus /
As you can see, the final page has the same content, although there are 2 different links to it . In the category laptops there is a subcategory for accessories, which includes the category targus (there is such a firm).
The second link was created for ease of navigation, since the bags for laptops are also an accessory. If you use the 301st redirect, then the buyer will be automatically redirected to the first link, and this is a completely different section and the buyer will be misled. If he wants to look for a bag from another manufacturer, then he will have to go again to the electronics section, then accessories, etc. Does he need this? Yes, and we, too. It is easier to use here a canonical tag pointing to the original:
. link rel = ”canonical” href = ” http: // www. example. com / travel / luggage / laptop-bags / targus / ”/.
All. PS robots are now clear where the original, and where the duplicate. Everyone is happy.
The alternative link tag is similar to the canonical tag. It is mainly used for international or multilingual SEO purposes.
. link rel = ”alternate” hreflang = ”en” href = ”http: // www. example. com / path ”/.
. link rel = ”alternate” hreflang = ”en” href = ”http: // www. example. co. uk / path ”/.
. link rel = ”alternate” hreflang = ”en” href = ”http: // www. example. com. au / path ”/.
The canonical tag completely excludes all duplicates from the index, while the alternative tag stores them in the index. This 1) helps PS (Google) to select the appropriate page depending on the region or language and 2) fixes a problem with duplicate content.