Free Online Plagiarism Checkers and Duplicate Content Detectors

Free Online Plagiarism Checkers

I have rounded up the most powerful (free!) online plagiarism checkers to prevent you from duplicating or (accidentally) plagiarizing text. Of course, you can use these same plagiarism detectors to identify plagiarists who are stealing your content or republishing your articles without your permission. I have thoroughly tested each of these plagiarism checkers to make sure: 1) they actually catch plagiarized material; 2) they actually find duplicate content; 3) they analyze your entire text, including words, phrases, sentences and paragraphs; and 4) each one is fast, reliable and free to use.

Stop the Copycats and Plagiarists Now!

Let's face itthe Internet harbors many "copycats" who steal other individual's creative works. These copycats have no respect for the creator of the work, nor do they have any respect for how long the creator has labored to create that work.

I've been a victim of plagiarism several times (unfortunately) over the last 10 years. I've found several of my articles completely ripped off, or slightly reworded under somebody else's byline, or chopped up into pieces and reused by spammers to create bogus websites.

If you write articles for clients or publish your own material online, it's not a question if a plagiarist will steal your content; rather, it's when a plagiarist will steal your content.

These free plagiarism checkers and duplicate content detectors will help:

1) freelance writers who need to know if anyone is stealing their articles; or to find out if an editor is republishing their articles on other websites;

2) students who are writing a research paper, dissertation, or thesis paper and need to double-check that they are citing all sources and not plagiarizing material;

3) academic researchers who extract research results from articles and journals and need to double-check that they have credited the original source.

4) teachers and professors who want to find any copied, duplicated or plagiarized text in students' papers.

5) anyone who writes and wants to avoid plagiarism or find out how many idiots are stealing their content without permission.

Free Plagiarism Checker # 1:

PlagTracker [ visit website ] uses its own special scanning formula that searches your content for any signs of plagiarism. College and high school students can check their papers for any phrases of plagiarized text or duplicate phrases/sentences.

PlagTracker first scans your entire text, checking it against a large amount of Internet websites and its own database of 20 million scholarly works.

PlagTracker offers a free version which allows you to scan a text of up to 5,000 words. Simply paste the text into its box, click on "Start Checking," and watch the progress bar zoom to completion. The next screen will provide you with a detailed report. I was able to scan an article of 1,000 words in less than ten seconds.

Once PlagTracker has finished scanning your text, it will produce a "Plagiarized Report" for you to see how many instances in your text is (potentially) plagiarized. To the right of the report, you will notice a link called "View all Sources." Click on this link, and it will reveal the online sources where it has found instances of plagiarized text. Click on the link next to the online source to visit the website that has the plagiarized text.

A percentage shows up on your report to tell you how much of your text has been plagiarized or duplicated. For instance, if you get 80%, it means exactly that80% of your text seems to be plagiarized. Sample Report
PlagTracker's "Plagiarism Report" highlights all instances of plagiarized text, including links to the website. It will also let you know how many sources contain your plagiarized text.

Free Plagiarism Checker # 2: [ visit website ] offers a free "plagiarism detector" tool that searches for several phrases of text that you paste into its search box field. This plagiarism checker is a basic, "bare-bones" tool that uses Google's own search engine to match phrases of text. Naturally, you could go to and input a brief sentence of text with quotation marks to find exact matches of text on websites; but bypasses this step and uses its own quotation marks and special "search engine" operators to search for passages of text.

You can type in or paste your entire text into the tool, hitting the "Enter" key after each sentence. When you click "Submit," Google's search results screen will appear with exact matches of your text at other websites, which is a good indicator of plagiarized text. also allows you to enter a specific URL to a webpage to find any duplicate version of it across the Internet. Sample Screen
At, paste or key in your text, then click "Search." Within seconds it will search for any instances of plagiarized or duplicate text and provide you with direct links to the websites.

Free Plagiarism Checker # 3: [ go to website ] is another plagiarism detection tool that will match your text to identical text appearing on other websites across the Internet. It functions the same way as, but takes the checking process one step further. Instead of just listing links with brief descriptions of websites that match your text, it will highlight all plagiarized text on that website. The visual highlighting of text can immediately tell you how much of your text is plagiarized or duplicated word-by-word at that website.

You can type in or paste in the text that you want to detect for any issue of plagiarism. This can be sentences, paragraphs, or an entire article. also has an option to upload a text file in lieu of copy and paste. Sample Results
Once you hit the "Search Button," it will take a few seconds to get the results. If it finds any instances of duplicated text, phrases or sentences, it will provide a direct link to the website. Next to each result is a button called "Compare Text," which will take you to the website, highlighting all instances of duplicated text at that website.

Free Plagiarism Checker # 4: [ visit website ] lets you key in or paste a text size of up to 25,000 characters. You can choose to find instances of duplicated text across three areas: 1) the entire web; 2) News; or 3) social networks. The default setting is to search across the web. also includes some advanced search options that allow you to decrease or increase the relevancy of text that it finds.

Simply paste your text into the large search box and click on "Quick Search." Within seconds, will break your text into paragraphs, sentences, phrases and words and check for duplicate content. across the Internet. It will display the results on the same screen. To view duplicated or plagiarized text at a website, click on the link. A floating windows will appear displaying the website containing the duplicated text. highlights all instances of duplicated text in yellow, so you can easily see what text is duplicated. Sample Results
Simply enter your text in the large search box, and hit "Quick Search." Results appear below on the same screen.

Free Plagiarism Checker # 5: [ visit website ] is another online plagiarism checker but with more useful features than the other ones I've mentioned above. Besides checking for plagiarized content and duplicate text across the Internet, it will also analyze your text for proper spelling and grammar, the syntax of your words in a sentence, the choice of words, and your entire text's readability level (i.e. the estimated grade level that a person needs to read your text.) Sample Results
PaperRater is fast and user-friendly. At the homepage, click on the large button called "Use Now Free!," and then type in or paste your text into the large search box. You also must provide a title of the text/article, your education level, and the type of paper you're submitting, such as a research paper, essay, narrative, speech, thesis, and so on. Make sure you select "Originality detection (optional): Include (Slower)."

Free Plagiarism Checker # 6: [ go to website ] takes slightly more time to process and analyze your text and to find any instances of duplicate or plagiarized text across the Internet. My 800 word article took about 1 minute to process, whereas the other plagiarism checkers took less than twenty seconds. Despite the slightly longer time, works flawlessly and very effectively.

First, you will need to register for an account because will create your own "space" to store all previous text and files that you had processed. You can paste in text or upload a text file. Then click on the button called "Check Plagiarism." When PlagiarismCheck has finished processing your text, the status will change from "Check in progress" to a hyperlink called "View Results." Simply click on the link to view the results. It will list all websites with their links that contain the duplicated text. You can also move your mouse across the highlighted text to determine which phrases, sentences or paragraphs are duplicated and at which websites. Sample Results conveniently highlights all instances of plagiarized text, and includes the websites with their links where it has found the plagiarized text.

Free Plagiarism Checker # 7: [ go to website ] offers a suite of useful plagiarism and duplicate content checking tools that tap into major search engines as well as popular archival resources such as Google Books and Google Scholar. Although you can use its services immediately for free, I recommend you register for a free account. With a free account, you have no restrictions as to word count or services. I was able to register within 10 seconds. To check for any instances of plagiarized content across the Internet, select the option called "Check Plagiat." You can either paste your text into the large text field or upload a text file. For best results, tick the circle next to "Google" to have it use Google. You can also repeat the process with Bablyon and Yahoo!, but I found that using just Google is enough. You also have the option to match your text exactly, or to match relevant or similar text. Next click on "Check Duplicate Content." takes longer to process your text than other plagiarism checkers, so you may have to wait a minute or two, depending on the size of your text. Sample Results will list all results on the same page. analyzes and processes each complete sentence and compares it to's results. If your sentence is unique, the word "unique" will appear under "Results." If it finds instances of duplicate or plagiarized text, it will list the number of occurrences under "Results." To jump to the website that contains the duplicate text, simply click on the link.

Experiment with's other unique features, such as checking for duplicate or plagiarized text at Google Books and Google Scholar. Students who are working on a thesis paper or dissertation will find these features useful to make sure they are citing all quoted sources and not plagiarizing any source materials.

Brian Scott