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

Is Turnitin free for students?

Not directly. Turnitin’s help centre says it doesn’t sell individual licences; its similarity products are licensed to schools, universities and other organisations. If your university has a licence, using it costs you nothing extra, and you get access through a course, the library or a research office. If it doesn’t, there is no personal Turnitin account to sign up for. The only product Turnitin sells to individuals is iThenticate credits, which are paid and aimed at manuscripts; our iThenticate guide explains that route.

For PhD scholars in India, the more relevant question is usually not Turnitin at all. Under INFLIBNET’s ShodhShuddhi programme, member universities receive DrillBit plagiarism detection software, and research scholars and faculty can be given accounts by the university coordinator. Many universities run the final thesis check through the library on DrillBit. Our DrillBit guide covers that process step by step.

The UGC 2018 plagiarism regulations also matter here. They require each institution to adopt a technology-based checking mechanism, and they require you to submit an undertaking that your thesis was checked with a tool approved by the institution. However carefully you check your work on a free site, that result can’t replace the university’s check.

What free plagiarism checkers compare your text against

A similarity checker can only find a match with text it can see. That is the single biggest difference between a free checker and the tool your university uses. Most free checkers search openly available web pages. Paid institutional tools also search subscription journal articles supplied by publishers and, in Turnitin’s case, papers submitted by students at other institutions.

The table describes typical free checkers, and individual products differ. Some free tools are cut-down versions of paid ones. Grammarly, for example, says (as of September 2026) that its checker compares text against over 16 billion web pages and academic papers in ProQuest’s databases, and that its Premium plan highlights the passages that need citations. Whatever the free tool, read its own description of what it searches before trusting a low number.

The gaps that matter most for a thesis are the second and third rows. A literature review built from journal articles, or a methods chapter adapted from a senior’s thesis, can look clean on a free checker and still match heavily on the university’s tool.

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

It is common for a chapter to get a low figure on a free website and a much higher one on the university’s check, or the other way round. Three things explain most of the difference:

1. Different content. As the table shows, each tool searches its own collection, and the institutional tools see far more academic material.
2. Different settings. Institutional checks for theses usually exclude references, properly quoted text and very short matches. Many free checkers don’t let you set these, so their figure can be higher for a chapter with a long reference list, or lower because they ignore short fragments altogether.
3. Different matching rules. Tools differ in how many consecutive words make a match and how they treat small changes in wording.

So neither number is the “real” one, and you can’t convert one into the other. The figure that counts is the one produced by your university’s tool with its settings. For how to read that report, see our guide to reading a Turnitin report, and for the permitted levels, our plagiarism limits guide.

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

An unpublished thesis is years of your work, and it isn’t yet on Shodhganga or anywhere else with your name and date on it. Before you paste it into a website, think about what happens to it next.

Privacy and ownership

Read the site’s privacy policy and terms before uploading. Some checkers say clearly that they don’t store or share your text. Others are vague, or give themselves broad rights over what you upload. A site that doesn’t tell you what it does with your text is not a safe place for a full thesis.

Your own draft matching your final thesis

Institutional tools can store submitted papers in a repository and compare later submissions against them. Turnitin, for example, lets institutions store submissions in its standard repository, in a repository private to the institution, or not at all. If a draft chapter goes into a repository through someone else’s account, your final thesis can later match it, and the report will show a match to a paper that isn’t in your name.

Buying a “Turnitin report”

Turnitin or iThenticate reports sold by websites and agents are run through an account that belongs to someone else, outside the purpose of that institution’s licence. You don’t know where your file goes, whether it is stored and in whose name, or whether the report you receive used the settings your university uses. It is the least safe option on this page, and it doesn’t give you anything the university route can’t.

Borrowing a senior’s or friend’s login

Running your thesis through a senior’s or friend’s university login carries the same risks on a smaller scale. The file may be stored in a repository under their name, so your final thesis later matches a paper that isn’t yours, and the check still isn’t the one your university asks you to declare.

The safe route is the one your university already provides: ask the library or research cell, as described below.

When a free check is still useful

Free checkers have their uses. Used for the right job, with text you don’t mind sharing, they can help:

• Checking a paraphrase. If you have rewritten a paragraph from a web source, a free check shows whether it still follows the original too closely.
• Finding a source you forgot to cite. A match to a web page you used but didn’t reference is a prompt to add the citation.
• Spotting copied background text early. Definitions and general background copied from websites show up on almost any checker.

Keep free checks to short passages rather than whole chapters, and treat a low score as “no obvious web copying”, not as “this will pass”. A free checker’s result isn’t accepted by universities as evidence of originality, so keep it for your own use. If a passage needs work, our paraphrasing and quoting guide shows how to rewrite and cite it properly.

How to get a proper check before thesis submission

Start with your research cell or central library, well before your submission deadline. Most universities publish the procedure on a notice or on the library website. When you ask, find out:

• Which tool and which settings the university uses for thesis submission, and whether references, quotations and small matches are excluded.
• How many checks you are allowed before the final one, and whether chapters can be checked separately.
• What the certificate needs to show, so the final check produces the document your submission form asks for.
• Whether the report is shared with you, including the source list and highlighted passages as well as the percentage.
• Whether the file will be stored in a repository, so a later check of the final thesis doesn’t match your own draft.

If your university gives you a DrillBit or Turnitin login, check chapters as you finish them rather than the whole thesis at the end. It is much easier to fix one chapter’s matches than to revise six chapters in the week before submission.

When the report shows passages that need rewriting, the fix is careful revision: your own wording, proper quotation and full citation. Our similarity reduction support works through the report with you on that basis.