How to Check for Duplicate Content

Learn in this guide how to check & find duplicate content to improve SEO, in addition to plagiarism detection & tips and tools

How to Check for Duplicate Content Plagiarism Detection Tools

In a nutshell, duplicate content is content that is identical and can be accessed on two or more different URLs. The duplication can occur: Firstly, within your own website. Secondly, in cross-domain duplication occurs when another website copies your content. Learn in this guide how to check & find duplicate content to improve SEO, in addition to plagiarism detection & tips and tools.

How to Check for Duplicate Content

CopyScape duplicate content checker

There are a lot of tools to find duplicate content. One of the best-known duplicate content checkers is probably This tool works pretty quickly: insert a link in the box on the homepage, and CopyScape will return a number of results, presented a bit like Google’s search result pages.

Use the CopyScape duplicate content checker to find copied content from your website on other websites. Again, it’s one of many tools, but this one’s free and easy to use. Keep in mind, though, you won’t get unlimited scans for one website. If you want to dive a bit deeper into your duplicate content, CopyScape also offers a premium version for more insights.

Using CopyScape, we frequently find manufacturer descriptions used in online shops to be duplicate. Usually, these are automatically imported into the shop’s content management system. Moreover, not just for your website.

Be aware of this. We understand it’s quite a hassle to write unique product descriptions for every product. However, don’t your best-selling products, at the least, deserve as much? So start now and take it from there!

Siteliner internal duplicate content check

Siteliner is CopyScape’s brother that searches for internal duplicate content. So, this duplicate content checker will find duplicate content on your own site. Keep reading this tutorial to learn how to check & find duplicate content to improve SEO, in addition to plagiarism detection & tips and tools.

Duplicated Content Internal Checker

Internal Duplicated content, how does that happen, you ask? Well, a very common example of this is when a WordPress blog doesn’t use excerpts but shows the entire blog post on the blog’s homepage.

That means that the blog post is available on at least two pages: the homepage and the post itself. And it’s probably on the category and tags overview pages as well. That’s four versions of the same article on your website already.

Using excerpts (rather than showing the entire post) has the advantage that the excerpt always has a proper link to the post. This link will tell Google that the original content is not on that blog/category/tag page but in the post itself. We often recommend the use of excerpts.


The Siteliner duplicate content check will show you a lot of things but limited to 250 pages and once every 30 days. Again, there is a premium version, but the free one will already give you a good impression. Just search and you’ll end up on the overview page. You’ll see the percentage of internally duplicated content at the top left.

Don’t panic when you see high numbers, as this duplicate content check also considers excerpts duplicated content: Simply click one of the links and check if it’s indeed the excerpt. It obviously links to the post, so if that’s the case, you’re covered.

Extra Tips: Duplicate Content Tools

While Google understands what a sidebar is, CopyScape and Siteliner appear to include all text on a page in their percentage calculations using the plagiarism detection tools.

This means that the actual percentage of the duplicated content, when just looking at the main content of a page, might be higher. Please keep this in mind when you use one of these duplicated content checkers. Just a heads-up!

Manually Check

CopyScape and Siteliner are nice, easy-to-use duplicate content checkers. However, if you want to see what’s duplicate according to Google, you could also use Google itself.

If you have a certain page that you’d like to check, go to that page. Copy a text snippet, preferably from a section that you think might be attractive for others to copy.

Let’s take a passage from our common SEO mistakes article: “If your page title is too long (currently 400 to 600 pixels), it will get cut off in Google. You don’t want potential visitors to be unable to read the full title in the SERPs.

(Note that Google only takes the first 32 words into account). Insert the exact snippet in Google between double quotation marks like this:

According to Google, this search query returns ‘about 208 results’, which is well over the 10 results CopyScape returned.

Plagiarism Detection Tools: Duplicate Content Tips

  1. Grammarly: While primarily known as a grammar and spelling checker, Grammarly also offers a plagiarism detection feature. It scans your content and compares it to a vast database to identify any potential duplicate content.
  2. Screaming Frog SEO Spider: This powerful desktop tool is widely used for website auditing. It can also detect duplicate content by crawling your website and generating reports highlighting any duplicate pages or content.
  3. SEMrush: SEMrush is an all-in-one SEO suite that provides various tools for keyword research, backlink analysis, and content optimization. It includes a “SEO Content Template” feature that can help you avoid duplicate content by providing recommendations based on top-performing pages.
  4. Moz Pro: Moz Pro is another popular SEO platform that offers a range of features for keyword research, site auditing, and link analysis. Its “Site Crawl” tool can help you identify duplicate content issues by scanning your website and providing detailed reports.
  5. Plagspotter: Plagspotter is a dedicated plagiarism checker that can scan your content and compare it against a vast database of online sources. It provides a percentage match and highlights any potential duplicate content.
  6. CopyGator: CopyGator is a free online tool that monitors your website’s RSS feeds and detects instances of duplicate content. It alerts you whenever it finds content similar to yours on other websites.
  7. DupliChecker: DupliChecker offers a range of SEO tools, including a duplicate content checker. It scans your content and compares it against its database to identify any matches, helping you maintain originality.
  8. Google Search Console: Although not specifically designed for duplicate content detection, Google Search Console can be a valuable tool. It allows you to check for indexing issues and manual penalties, which can indirectly help identify duplicate content problems.


People expect to find unique and helpful content, and that’s what they should be able to find. Duplicated content should be avoided as much as possible. Content should be well-created and unique so that readers can have the best online experience.