Search engines such as Google, Yahoo and Bing check your website’s content to make sure it’s unique. Besides the fact that duplicate content ranks poorly in search engines, it’s also a waste of time to go through the effort of adding content to your site (only to discover that nobody is viewing your page because the content is re-used).

Whether you are a copywriter that wants to check if your content is unique (doing research online can lead you to copying somebody else’s work unintentionally when you are writing quickly) or you own an ad agency and you are outsourcing work to a number of copywriters, it is a good idea to use some sort of plagiarism detection tool or software.

Copyscape
Copyscape is one of the most effective and widely used plagiarism tools on the internet. This content analyzes your web page and searches for matching content on the internet.

How it works: You copy and paste the link into the Copyscape search engine (you can check it out at www.copyscape.com) and it will present you with a list of search results and links with matching copy. This tool isn’t free, but it is relatively cheap. You can pay per search or you can pay in advance to have a number of articles checked.

Plagium
This plagiarism detection website recently announced that its service will be free. Like Wikipedia though, it accepts donations in order to maintain, develop and improve the service. The site works differently to Copyscape: You don’t paste a link into the search bar, you copy and paste your text from Microsoft Word of Notepad. This option may work better for writers who want to check their text before it is uploaded to a website.

One of the neat benefits of this plagiarism detection tool is that it also offers an alert feature that notifies you if somebody uses your copy. This function also sends you a link so that you can see where your copy has been used.

eTBLAST
eTBLAST works well if your site is publishing lots of academic content. It may not be as efficient as Copyscape or Plagium in picking up a number of small similarities, but it is a good tool if you are trying to pick up duplicate publication of your articles.

Other plagiarism detection tools you can check out include Chimpsky (www.chimpsky.uwaterloo.ca), Crosscheck (www.crossref.org), iplagiarism (www.iplagiarismcheck.com) and CopyTracker (www.copytracker.ec-lille.fr).