Duplicate content affects your SEO performance by preventing your valuable content from getting high search rankings and the traffic it deserves.

But how does it happen exactly? And are there ways to avoid it?

This article provides all the details you need to know about duplicate content. We’ll highlight its impact on your SEO efforts and identify its causes.

Then, scroll down further to learn how to check and free your site from duplicate content issues.

What is Duplicate Content?

Duplicate content is any content that appears in several places on the Internet, within or across domains.

It can be blog articles published on various platforms or product descriptions found on multiple pages within your site.

A duplicate can be an exact or similar copy of the content. Also, it can be unintentional or done on purpose.

Why Do You Need to Avoid Duplicate Content?

The effect of duplicate content on SEO performance is probably every website owner’s top concern.

And the short answer to this is, yes, duplicate content can hurt your SEO efforts. However, it won’t lead to penalties unless the duplication aims to deceive or manipulate search results.

Still, there are valid reasons why you should avoid or address this matter.

1. It’s a waste of crawl time.

Bots visit websites to crawl and index their content. They also recrawl pages to check for updates or changes created.

These bots act as librarians, in a way, who receive new books, check them, and then categorise them into the search engine library.

But they can only work on each site for a limited time. So, having several duplicates means more unproductive work for the bots.

Worse, duplicates also delay your fresh, best or enhanced content from getting indexed and appearing on the search results.

2. It confuses search engines.

With so many websites, search engines like Google can only show a few results to their users. And they prefer to display the best.

But too many duplicates make it harder for search engines to do this. Worst-case scenario, they end up showing or ranking the wrong pages.

For site owners, it’s also problematic when less preferred versions outrank the more informative original pages.

Why Avoid Duplicate Content Issues

4. It dilutes link equity.

Getting backlinks or having other websites link to your site is crucial to SEO success.

But duplicate content forces websites to choose between multiple page variations. In turn, the backlink reduces its value.

Similarly, your internal link strategy is also affected. Instead of directing readers or visitors to one page, they end up landing on different but similar pages, which impacts overall content visibility.

Duplicate content makes your site look cluttered, too, which can frustrate users, boost bounce rates and affect traffic.

5. It creates lots of unfriendly URLs.

Each duplicate content you make gets a unique address or URL. But some generated URLs can be as messy as “domain.com/page/?utm_content=duplicate&utm”.

Messy URLs are difficult for online users to read and decipher. They look rather suspicious, too.

And so, most people are less likely to click them, which, in turn, affects site traffic.

Moreover, search engines find it hard to use messy URL data for indexing.

Without a doubt, duplicate content is an SEO issue. Specifically, it limits your online presence, disrupts your link-building strategy and lowers your ranking potential.

What Causes Duplicate Content?

We now understand how duplicate content affects your SEO performance. And the initial step to avoiding this problem is to know why it happens in the first place.

There are two causes. One is that you may have unintentionally created it within the same domain. We call this onsite duplication.

On the other hand, offsite duplication occurs when two or more websites publish the same pieces of content.

Let’s look at these two in more depth.

Causes of Duplicate Content

A. Duplicate content on the same domain

Onsite duplication typically happens due to poor site architecture or website development. If you fail to apply search-friendly best practices, you are only flushing your SEO efforts down the drain.

But the good news is, this type is something you can control. Specifically, your site admin or web development team can quickly work on it.

Here are some typical sources of onsite duplication.

1. Redundant URL versions

There are several ways how you might encounter this issue:

  • HTTP vs HTTPS. After installing an SSL certificate, you get two versions of your website: HTTPS:// and HTTP://.
  • Non-www vs www. Most websites will have these prefix variations visible to users and search engines.
  • Trailing slashes. These are the forward slashes you often see at the end of URLs. Their counterpart versions are URLs without trailing slashes.
  • Case sensitivity. URLs are case-sensitive. That means “https://www.infiniteace.com/blog/” and “https://www.infiniteace.com/BLOG/” are two different URLs with the same content.
  • Mobile and print-friendly URLs. These are alternate versions of the original content. And each carries a different URL.
  • Complex taxonomies. Site taxonomy refers to how you organise or classify your content. And it usually comes in two forms: categories and tags. However, tagging content to multiple classifications results in several URLs bearing the same content.

Imagine if all these URL versions are live. Each will lead to identical content and compete for the same search visibility. Search engines will also treat them as separate URLs.

Without proper redirects, consistent URL convention and server configuration, all these versions result in duplicate content and SEO problems.

2. URL parameters

eCommerce websites use URL parameters to display content according to specific queries or product searches.

These often appear as characters after a question mark, ampersand or equals sign within a URL.

This filtering function is helpful for visitors as it narrows down their searches.

However, it also creates an infinite number of URLs with multiple parameter combinations imaginable.

And each URL generated will show the same content.

This issue makes it hard for search engines to decide which URL to index. The lack of proper bot instruction to bots wastes crawl time, too.

3. Localisation

Do you own dedicated websites to cater to the international audience? It’s a non-issue if your sites target people who speak different languages.

However, duplicate content issues can happen when catering to people from different countries speaking the same language.

For instance, if you target American and British markets, both English websites will likely display similar or the same content.

It’s essential to know how to treat alternate websites like this to avoid duplicate content and SEO issues.

Multi-Regional Websites

4. Dedicated pages for images or comments

There are content management systems that generate separate pages for image attachments. Usually, these pages only contain the image and boilerplate copy.

These images are similar to all other auto-generated pages, resulting in several duplicates.

This issue also happens when you enable comments on your site.

Some content management systems would present them on pages, displaying the original content with the first 20 comments at the bottom.

Then, a different page or URL shows the next batch of comments with the same original content.

Not knowing how to manage these through relevant settings or plugins can be problematic.

5. Session IDs

A session is a history or record of your users’ activities within your site. And each activity gets an ID in the form of URLs.

These IDs are ideal for storing visitor information and web analytics. They also allow users to perform actions, like saving items to their wish list or shopping cart.

However, as each web activity is unique, every session ID also gets a new URL, even if they contain similar or identical content.

6. Staging or testing environments

When you want to try a new plugin or change the codes on your website, the last thing you’d do is apply it straight to your live site.

It’s best to test them in a staging environment first. A staging environment mirrors or nearly mirrors your website.

However, duplicate content and SEO problems arise when search engines index them. Protecting or limiting access to your staging environment is a must.

Duplicate Product Descriptions

B. Duplicate content on different domains

Offsite or cross-domain duplicates are a little more challenging to resolve. The reason? Settling them sometimes means dealing with third parties or website owners using copied content.

Here are some usual sources of offsite duplication.

1. Generic product descriptions

If you are managing an eCommerce website, you probably have hundreds or thousands of pages with product descriptions.

The problem is thousands or millions of retailers selling the same items have similar or identical pages. Most of them will likely display whatever product details manufacturers provide.

Duplicate content like these affects your SEO performance as you need to beat lots of competitors. It’s more cutthroat if you are in an industry with several established businesses.

One way to solve this is to gain a few links to the page. Remember that backlinks are a crucial search ranking factor. However, achieving this will take time.

A more viable solution is to make unique and optimised product descriptions. Perhaps, you can incorporate your first-hand experience with the product or add positive customer feedback.

Yes, it’s laborious and time-consuming. But the extra effort can make you look better in the eyes of search engines and your customers.

2. Content syndication

Attracting high-volume traffic to your website takes time, especially when it’s new. One way to speed up your progress is through content distribution or syndication.

It’s a process of republishing your content on other websites or platforms. Doing so increases your content views and reach.

However, this method can affect your SEO when the duplicate content gets good search engine rankings while your original version does not.

Websites with lower domain authorities often encounter this problem.

Also, bots frequently crawl websites with high domain authority, giving them a better ranking advantage.

Lack of coordination with your ally and the search engines can make this helpful technique work against your website.

3. Scraped content

Content syndication is like offsite duplicate content with permission. On the other hand, scraped content is its unethical opposite.

These content scrapers or spammers are known offenders of stealing content and reusing stolen articles for their benefit.

This problem is hard to address. And usually, the best solution is to ignore it and hope search engines will recognise you as the original author.

You can also send Google a copyright infringement report to remove the scraped content from the search index.

Adding proper tags and codes or using absolute links within your content may help protect it, too.

Original vs Copy

How Do You Check for Duplicate Content?

You can try one of these methods to audit your site for duplicate content.

Method 1: Use Google

Copy a few words or the first sentence of your page, then paste it with quotes on Google. Ideally, the search result should display your webpage only.

If other pages are showing up, check if your page is at the top. If not, it might be a duplication issue.

Try searching a few other random sentences within the page to confirm.

You can also check by going to the “coverage” tab of your Google Search Console and then ticking the “excluded” box. It should show you a report of duplicate content issues in different categories.

Method 2: Use free content checkers

Creating 100% original articles is difficult, considering the number of websites and pages available online.

There’s a high chance that other authors have previously written something about your topic and even used your exact phrases to discuss it.

But you can make yours unique by using content or plagiarism checkers. And you don’t even have to spend anything to use them.

Here are some tools you can use for free:

  • DupliChecker. Use this to check your content for plagiarism before publishing it. You can also use it for checking published content. It’s free, but you only get a limited number of searches.
  • Copyscape. This comparison tool lets you check your original content with another published page. It can also highlight duplicate content and display the extent of exact matches in percentages.
  • Plagspotter. This tool can help verify if a website uses your content without permission. It can also automatically monitor your URLs weekly to check for duplicate content issues. A similar tool called Siteliner can also perform monthly content monitoring plus check for broken links.

Method 3: Use premium content checkers

Paid plagiarism checkers work with better algorithms, giving you more detailed and reliable results. In addition, some can even generate reports or proof that your content is the original one.

Some good premium tools you can use are:

  • Plagium. This tool has a Quick Search option to scan your content for free. But its premium Deep Search option allows in-depth plagiarism checking. It also has a File Search option for comparing text documents.
  • Plagiarismcheck.org. This tool is available for organisational and individual use and checks content through different payment plans. It’s ideal for identifying paraphrased content and exact matches.
  • Grammarly. The free version of Grammarly is ideal for checking grammar, sentence structure, spelling, punctuation and word choice. It also has a premium version for individual and business use that allows in-depth grammar checking and plagiarism detection.

How to Fix Duplicate Content

How Do You Fix Duplicate Content?

After locating a duplicate content issue, your next step is to evaluate it before making any changes.

For instance, you can check how similar your page is to the other published content. Are they exact or near-duplicate matches?

You can further assess duplicate pages by identifying their intent. Tool checkers won’t spot this, but human readers can.

Also, check how visitors interact with it. Is it getting more traffic or engagement than yours?

Once you are sure that the duplicate content is affecting your SEO performance, you can apply the following solutions.

1. Use the canonical and hreflang attributes

  • Problem to solve: redundant URLs and localisation

Adding a canonical tag to the HTML head of duplicate pages lets search engines know that these are copies of the original.

Canonicalisation instructs search engines to credit all SEO attributes and ranking power to a preferred page.

It helps define mobile and print-friendly versions of a desktop or web page. You can also use it when publishing your content on multiple platforms or websites.

There are two types of canonical tags, though. One tells search engines that another page is the canonical version.

The other is a self-referencing type or a canonical tag that identifies the page as the original.

For websites targeting multiple regions with the same language, use the hreflang tag to avoid duplicates.

2. Set up a 301 redirect

  • Problem to solve: redundant URLs

Creating a 301 redirect means assigning a master page or canonical URL for all other alternate URLs. It should prevent your pages from competing with one another and boost content relevance.

For example, if your master or canonical URL is https://www.infiniteace.com/, all other URL variations with HTTP, www or without a trailing slash should point here.

Keep in mind that this solution is not limited to your homepage. It applies to all other alternate URLs of individual pages.

When you do this, avoid making multiple redirect hops to keep the page loading speed up, reduce server bandwidth and minimise future issues.

301 Redirect

3. Practise good URL categorisation

  • Problem to solve: complex taxonomies

Study your site taxonomy and streamline it. Map out your web pages, then assign each with a unique H1 and quality keyword.

Next, organise your content into clusters. It should help you create a structure that minimises duplicate content creation.

Finally, designate a master category for your pages, if possible. This tip can help eCommerce sites manage their product pages with minimal effect on user experience and SEO performance.

4. Master URL parameter handling

  • Problem to solve: URLs with multiple parameter combinations

Identify which URLs need crawling and which parameters bots can ignore. That way, you don’t waste the crawl budget and avoid duplicate content issues.

For example, you can instruct Google (or any search engine through the proper tools) to crawl all landing pages and canonical URLs.

Then, you can add the correct canonical tags to indicate unnecessary tracking parameters.

These tags should help you communicate with the search engines and instruct them on what action to take.

5. Apply the meta robots “no index” tag

  • Problem to solve: staging environments getting indexed

Marketers often use duplicate content to create staging environments or landing pages for advertisements. These are useful for gathering data or testing changes before they go live.

But you don’t want bots to index these and display pages without value on the search results page.

So, add the “no index” tag to the HTML code of your test page. This code should signal search engines to crawl the page but not index it.

It’s ideal if you need granular blocking of a specific page or file.


SEO experts used to think that duplicate content is disastrous. But that myth was long gone. We now know that it is not grounds for a penalty.

Still, you can and should fix duplicate content issues. As a website owner, it is your priority to present pages and content that will not confuse visitors or search engines.

So, make it a habit to use clean and consistent URL variations, produce unique and high-quality content, and do regular site monitoring.

Going the extra mile should reward you with high search ranking, visibility and organic traffic.

And while you’re at it, make sure to check your site for outdated content, too.