Free plagiarism checkers vs Turnitin: what a free check can tell you

Is Turnitin free for students?

Not directly. The Turnitin help centre clearly says it does not sell individual licences. Its similarity products are licensed only to schools, universities and other organisations. If your university has a licence, you pay nothing extra, and access comes through a course, the library or a research office. With no licence, there is no personal Turnitin account to open. For individuals Turnitin sells only one thing, iThenticate credits. Those are paid, and they are meant for manuscripts. Our iThenticate guide covers that route in detail.

Everybody talks about Turnitin, but for PhD scholars in India the actual question is mostly about some other tool. INFLIBNET runs a programme called ShodhShuddhi, and under it the member universities receive DrillBit plagiarism detection software. The university coordinator can then make accounts for research scholars and faculty. In many universities the final thesis check happens in the library itself, on DrillBit. The full process is in our DrillBit guide, step by step.

Then there are the UGC 2018 plagiarism regulations. As per these rules, every institution has to adopt a technology-based checking mechanism. You as the scholar also have to give an undertaking that the thesis was checked with a tool which the institution has approved. So you may check your chapters very carefully on a free site, still that result does not take the place of the university check.

What free plagiarism checkers compare your text against

A similarity checker finds a match only with text it is able to see. This is the biggest difference between a free checker and your university tool. Most free checkers search open web pages. The paid tools that universities buy also search journal articles kept behind a paywall, which the publishers give to them. Turnitin goes one step more and searches papers submitted by students of other institutions as well.

The table is about a typical free checker, and every product differs. A few free tools are smaller versions of a paid product. Grammarly is one example. As of September 2026 it says its checker compares text with over 16 billion web pages and with academic papers in ProQuest’s databases. It also says the Premium plan highlights the passages which need citations. So first read what the free tool itself says it searches, then only believe a low number.

For a thesis, the second and third rows of the table are the gaps you should worry about. Suppose your literature review is built mostly from journal articles. Or your methods chapter is adapted from one senior’s thesis. On a free site those chapters may show almost nothing, and then heavy matching comes in the library check.

Why a free checker’s percentage differs from your university’s

Many times a chapter gets a low figure on a free website and a much higher one in the university check. Once in a while it goes the other way round. Mostly the gap comes from the three reasons given here.

1. Different content. Every tool has its own collection to search, as in the table above, and the university tools can see much more of the academic work that is published.
2. Different settings. For theses, the university check usually leaves out references, properly quoted text and very short matches. Many free checkers give you no option to set these. Because of that, a chapter with a long reference list can get a higher figure there. Or the figure comes lower, since short fragments are ignored completely.
3. Different matching rules. Each tool has its own idea of how many words in a row make a match. Small changes in wording are also treated differently from tool to tool.

So you cannot call one number the “real” one, and there is no way to convert one into the other. Only the figure from your university tool, with the university settings, will count. To understand that report properly, read our guide to reading a Turnitin report, and discuss about the highlighted parts with your guide. The allowed levels are in our plagiarism limits guide.

The risks of uploading your thesis to free or paid-for checkers

Your unpublished thesis has years of your work in it. It is not yet on Shodhganga or any other place carrying your name and a date. So before pasting it into a website, think where the text goes after that.

Privacy and ownership

First read the privacy policy and the terms of the site, and only then upload. A few checkers say in plain words that they will not store or share your text. Other sites write very vague things, or keep wide rights for themselves on whatever you upload. Some sites say nothing about where your text goes, and there we would never put a full thesis.

Your own draft matching your final thesis

Institutional tools can keep submitted papers in a repository and compare every later submission with them. Turnitin gives institutions three options, for example. Submissions can go into its standard repository, or into a repository private to that institution, or they are not stored at all. Now think of a draft chapter that went into a repository through somebody else’s account. Later your final thesis can match with it. Then the report show a match with a paper that is not in your name.

Buying a “Turnitin report”

Some websites and agents are selling Turnitin or iThenticate reports. They run your file through an account that belongs to another person, which is outside the purpose of that institution’s licence. You have no idea where the file goes, or if it is stored and in whose name. You also don’t know whether the report used the same settings as your university. Out of all the options on this page, this one is the least safe. And it gives nothing more than the university route.

Borrowing a senior’s or friend’s login

A senior’s or friend’s university login has the same risks on a smaller scale. Your file may get stored in a repository under their name. Later your final thesis matches with a paper that is not yours. Also, that check is still not the one your university wants you to declare.

The safe way is the route your university already gives, through the library or research cell, as explained further down.

When a free check is still useful

Free checkers do help, if you use them for small jobs and only with text you don’t mind sharing.

• Checking a paraphrase. Say you rewrote a paragraph taken from a web source. A free check will show if your version is still too close to the original.
• Finding a source you forgot to cite. Sometimes the checker matches a web page you used but did not put in the references. Then you know to add that citation.
• Spotting copied background text early. When definitions or general background lines are copied from websites, almost any checker picks them up.

Paste a paragraph or two at a time on these sites, never a full chapter. A low score only tells you nothing was copied straight from some open web page, and the chapter can still get a high figure in the library. Universities will not take a free checker’s result as proof that the work is original, so keep it for yourself. Some passage still looks close to the source? Our paraphrasing and quoting guide shows how to rewrite and cite it.

How to get a proper check before thesis submission

Go to your research cell or the central library well before the submission deadline. Most universities put the procedure in a notice or on the library website. When you meet them, clear your doubts on these points.

• Which tool and which settings the university is using for thesis submission. Also ask if references, quotations and small matches are excluded.
• How many checks you are allowed before the final one. Some places let you check chapter by chapter, so ask about that also.
• What the certificate needs to show. See which document your submission form asks for, and get that exact thing from the final check.
• Whether the report is shared with you. Get the source list and highlighted passages too, since with only a percentage you can’t fix anything.
• Whether the file will be stored in a repository. Your own old draft stored there can then match the final thesis.

If the university gives you a DrillBit or Turnitin login, check each chapter as you finish it. Don’t keep the full thesis for the end. Fixing the matches in one chapter is easy. Doing corrections in six chapters in the last week before submission is very hard.

Passages marked in the library report need rewriting by hand, one by one. Mostly we put the idea in our own words, and a line needed as it is goes in quotes with full citation. Our similarity report review works through the report with you in that same way.