Duplicate content in SEO: Everything you need to know

Through our SEO Agency Optimize 360

What is Duplicate Content in SEO?

Le duplicate contentor duplicate contentThis is a common problem in the field of Search Engine Optimisation (SEO).

This is the presence of two similar or identical versions of the same content on a website. Duplicate content can have a negative impact on the performance of a website and therefore its visibility in search engine results.

What is duplicate content?

Duplicate content refers to the presence of identical or very similar content blocks on several web pages, within or outside the same domain. This problem, which is often unintentional, can have serious consequences for a website's SEO, diluting its SEO power and confusing search engines such as Google.

To avoid this, it is crucial to create original and unique content for each page, to be equipped to detect duplicate content and to implement technical solutions such as 301 redirects tag and the canonical. By following these best practices, you'll help your website rank well and effectively.

1. The causes of duplicate content

Duplicate content can occur for a number of reasons:

Copying content : a user takes content from another site without authorisation (plagiarism) and publishes it as is on their site.
La content syndication : the voluntary or authorised sharing of content between different sites, for example via RSS feed.
Technical errors : if a site is poorly configured or has structural problems, it can unintentionally generate duplicate content.

2. The consequences of duplicate content for SEO

Search engines, and Google in particular, attach great importance to the quality and originality of content. When they detect duplicate content, they can :

Penalise the pages concerned: pages with identical or similar content may be downgraded in search engine results, or even excluded from the index if there is massive duplication.
Reduce the visibility of the site: a site with a lot of duplicate content can see its authority diminish and its pages rank lower in search results.

3. How do you detect duplicate content?

There are several online tools for checking whether your website contains duplicate content:

Copyscape : this service allows you to compare a URL to other pages on the web to find similarities or duplications of content.
Siteliner : This tool scans your website to identify similar or identical content and pages with a low diversity rate.

4. How can duplicate content be avoided?

To minimise the risk of duplicate content, follow these tips:

Create unique content and quality: Take care when writing your texts and don't copy the work of others. Give priority to creating new content rather than re-using existing texts.
Regularly check for duplicate content: use the tools mentioned above to check for duplicate content on your site.
Pay attention to the structure of your site: make sure there are no technical problems or configuration errors that could unintentionally generate duplicate content.

5. How do you manage duplicate content?

If you notice duplicate content on your site, here are a few solutions:

Delete or modify the pages concerned: if you have several pages with similar content, choose those of least interest and delete or modify them to add unique value.
Use the canonical tag : This tag tells search engines which version of a page to take into account when indexing, when several similar versions exist.
Set up redirects : if different URLs point to the same content, redirect them to the same page to avoid duplication.

6. The different forms of duplicate content

Duplicate content can take different forms:

Internal duplicate content : This is the presence of two identical or very similar versions of content on the same website. To solve this problem, unify the content in question and set up redirects to the final version.
External duplicate content : In this case, the duplicate content is present on different websites. The solution here depends on whether or not you own the rights to use the content in question.

7. The consequences of using consensual duplicate content

When content sharing is authorised or desired by the parties involved (content syndication), rules must be put in place to minimise the risks:

Clearly indicate the original source of the content: mention the source of the text and add a link to the relevant page.
Make sure that duplicate content does not rank higher than the original: respect copyright and avoid unfairly penalising the original source.

8. Unintentional duplicate content

In some cases, duplicate content can be created unintentionally due to incorrect configuration or a technical problem on your website. To solve this problem, you can :

Check the structure of your URLs: make sure that each URL leads to a single page and don't hesitate to use redirects if necessary.
Have a unique version of your domain name : prefer a version with or without "www" to avoid confusion.
Manage URL filters correctly: if you use Google Analytics or a similar tracking tool, don't forget to take into account URLs containing parameters and avoid having several versions of the same content.

9. Using duplicate content wisely

In certain specific cases, the use or creation of duplicate content can be beneficial to your site:

Translations : if you offer content in different languages, this necessarily implies partial duplication of these texts. Make sure, however, that you translate all the content and that you indicate the original version to search engines for information purposes.
Voluntary content sharing : when you authorise other sites to use your content (syndication), make sure that this does not harm the referencing of your pages by complying with the rules mentioned above.

10. Common mistakes to avoid

When it comes to duplicate content, certain mistakes can easily be made. Here's what to avoid:

Systematically relay the same content: if you have several websites, create unique content for each one rather than duplicating the same texts.
More and more formatted versions : printer, mobile, etc., it is important to centralise your displays on a single URL in order to avoid any risk of being penalised.
Content fragmentation : a site composed essentially of extracts from other sites (aggregators, directories) may be penalised for lack of originality and added value for the user.

In short, it is essential to define a editorial strategy and ensure the quality, originality and relevance of the content on your website. While duplicate content cannot always be avoided, it must be managed with care and rigour to minimise the associated risks and maximise the chances of good visibility in search engine results.