It is known that search engines detect websites that contain similar and duplicate content. This search engine tool permits users to verify the percentage of similar content between website pages. The search engine penalizes similar and duplicate websites, though the exact percentage/punishment system is unknown and varies from search engine to search engine.
It is important to be aware of websites with similar or identical content to your website, to avoid being labeled as a spammer and therefore blacklisted by search engines. It is also vital to be mindful of having similar content within your own website pages, such as with dynamic product catalog pages.