What is duplicate content? Causes and how to fix it

According to Matt Cutts (head of Google's webspam team) roughly 25% to 30% of the content on the web today is duplicate content, meaning it is copied or repeated from other pages.

That may sound normal, but it is why many websites drop in rankings for no clear reason, or traffic stays “meager” and can't get past competitors even after every kind of optimization. Google dislikes duplicate content because it makes it hard to tell which version is the original, wastes system resources and hurts the user experience. So what is duplicate content and how do you fix it?. Let’s MONA Media Let's find out.

What is duplicate content?

Duplicate content is when the same or nearly the same piece of content appears at more than one URL on the internet. It can happen within your own website (internal duplication) or across different websites (external duplication).

Content counts as duplicate when it:

• Has mostly the same wording, structure or layout as existing content

• Gives readers no new information or distinct value

• Has nothing of its own that stands out from content that already exists

Example: Say you have an article introducing a “sunscreen” product in your “News” section, then copy it word for word and post it again in the “Blog” category under a different URL. Even though the content is identical, it exists at two different paths, so Google still treats it as duplicate content.

On top of that, Google doesn't favor showing repeated content. When it detects duplicate content, the search engine struggles to decide which version to show, and often both pages drop out of the top results.

So if you want your website to be SEO website on top sustainable, spotting and handling duplicate content is a step you can't skip.

Why is duplicate content a problem worth fixing?

Many people think a duplicated article just needs “a small edit”. If you don't optimize the content to add distinct value, duplicate content can cause many problems for both user experience and the way search engine bots crawl your site.

When Google finds several identical versions of a piece of content, it doesn't know:

• Which page to show?

• Which page to drop from the index?

• Whether to merge or split link value across each version?

If it isn't clear, Google's bot may pick the wrong version for the top, or spread SEO strength evenly across several identical pages, leaving all of them weak and possibly even “dropping out of the top” of search results.

For people doing SEO, this means:

• Diluted content and fewer chances to appear in search results.
• Backlink value is split up, which weakens ranking.
• Lost traffic and a drop in the site's credibility with Google.

So if you're doing SEO without watching for duplicate content, you may be pulling your rankings down without knowing it.

How does duplicate content affect website SEO?

Does duplicate content really affect your strategy for full-scope SEO? Of course it does, and not by a little. Google always favors original content that gives users distinct value. So if your website has duplicate content, even partly, search rankings can fall, traffic can drop and revenue can suffer.

Here are the clear consequences if you don't fully deal with duplicate content.

Unwanted, unfriendly URLs appear in search results

One of the most common results of duplicate content is that Google may show an unwanted URL in search results.

For example, you have a SEO-standard articles at the main URL, such as: domain.com/dich-vu-seo/ short, clear and user-friendly.

However, if that content is repeated at other paths such as:

• domain.com/dich-vu-seo-web/?utm_content=buffer&utm_medium=social.

• domain.com/category/seo-website-chuyen-nghiep-tai-ho-chi-minh/

then Google may well choose to show one of the other two URLs instead of the original one you want to SEO domain.com/dich-vu-seo/ 

What are the consequences?

• The URL shown is long, hard to read and lacks the main keyword, so users scroll past

• Lower click-through rate and less traffic 

• The ranking of the URL you want to SEO falls “with no brakes”, which hurts your keyword SEO plan

So if you don't fix duplicate content and your URL structure, you can lose traffic simply because Google “picked the wrong link” to show.

Slows down crawling

Normally, Google collects information from a website by “crawling” through each link, from page to page, to gather data and update content. 

But when it hits duplicate content, Google needs extra time to work out which version is the main one. This can slow the speed and frequency of crawling on your site, so new pages get indexed later, or updated pages aren't refreshed in search results in time.

Link equity gets spread out

When content appears at several URLs, each URL may receive its own backlinks from outside sites. That sounds good, but in practice it splits link value so it isn't concentrated on any one page.

This dilutes the power of your backlinks, so none of the URLs is strong enough to rank high on Google. Instead of putting all your effort behind one page, you are unknowingly sharing it evenly across several identical versions, and as a result no page is strong enough to stand out in the TOP. SERP.

So if you don't keep duplicate content under control, you weaken your own SEO strategy, however much you have invested in link building.

Content distributed across platforms can hurt ranking

Content syndication is when you let other websites republish your articles. But sometimes sites take your content without asking and post it themselves.

It gets worse when those sites rank higher than your original website in search results. Google may then treat them as the source of the content, and you are the one who loses everything.

What causes duplicate content?

Duplicate content isn't always caused by “copied content”. In practice, it can come from technical errors, content management mistakes or a website structure that isn't optimized. Here are the common causes of duplicate content:

URL variations

When you use URL parameters such as marketing campaign tracking codes, they can create several different URLs that lead to the same content.

For example:

• https://domain.com/san-pham/

• https://domain.com/san-pham/?utm_source=facebook

Although they show the same page, Google sees them as two different URLs, and if you don't handle this, they will be flagged as duplicate content.

HTTP vs. HTTPS, and www vs. non-www

If your website can be reached in several versions such as:

• http://example.com

• https://example.com

• http://www.example.com

• https://www.example.com

If an SEO-ready website and redirects aren't configured correctly, Google will treat each version as a separate page, causing duplicate content across the whole site.

Copying content from other websites

This is the most obvious and most common cause of duplicate content. When you copy an article from another source without naming it or changing the content, Google may treat your page as a copy and favor the original source.

Duplication within your own website

Creating too many pages with the same title or meta description, or categories and pagination pages showing the same content, can also cause duplicates.

A separate page for every image 

Some content management systems (CMS) such as WordPress create a separate page for every uploaded image. These pages usually have nothing but the image, and too many of them create many empty duplicate pages.

Using canonical or noindex tags incorrectly

When you place a canonical tag or a noindex tag in the wrong place, Google may misread it and index the wrong page, leading to duplicate content.

For example: All articles point their canonical to the homepage

No clear content strategy

Without a proper content development plan, several people on the team may write about the same idea, use the same keywords or repeat topics.

Example: Three different articles on the same site all cover “How to choose running shoes”, each 70–80% the same as the others → Google struggles to decide which page to prioritize.

How do you fix duplicate content?

Fixing duplicate content is an important step that not only improves user experience but also contributes a lot to lasting SEO results. Here are some simple, easy methods:

Use 301 redirects 

When two pages have the same content, use a 301 redirect to “tell” Google that URL A is the main version and URL B is secondary.

For example: If you change a path from domain.com/san-pham-abc sang domain.com/san-pham-moi, redirect 301 from the old page to the new one so you don't create a copy.

Add a canonical tag

When one piece of content can appear at several links (for example because of filter or sort parameters), Google may be confused about which URL to prioritize. A canonical tag lets you state clearly which URL is the main one.

Example: A product may be reachable at several URLs because of filters (color, size). Add a canonical tag pointing to the product's main URL.

Use the meta robots noindex tag

When some pages don't need to appear on Google (such as duplicate pages, product filter pages or internal search pages), you can add a noindex tag to the page's code. This tells Google's bot “don't include this page in search results”.

Build sensible internal links

When you link between pages on your website, make sure the link goes to the exact version you want Google to crawl. Avoid creating different links to the same content because of small URL differences, such as:

• With or without a trailing slash (/page and /page/ are two different URLs).

• http vs. https, or www vs. non-www.

Pointing to the wrong one can make Google think they are 2 different pages, creating needless duplicate content.

Check for and handle duplicate content on your website

To avoid being marked down by Google for duplicate content, check regularly for pages on your website with the same content. You can use SEO tools tools such as Screaming Frog, Google Search Console or SmallSEOTools to find them quickly.

When you find duplicates, handle them in one of these ways:

• Merge several similar articles into one, fuller and better article.

• Or edit and add new content to each page so they differ and have value of their own.

Optimizing content makes your website more appealing to both Google and users, which raises your chances of ranking and keeps visitors more effectively.

That is some of what we wanted to share with you about What is duplicate content? as well as the causes and the fastest ways to fix this problem on your website. If you have any questions or want advice on MONA's SEO services, contact us for support and to receive the SEO service price list quote.