How can I compare two documents for plagiarism?

Most online plagiarism checkers only have access to public databases, whose software doesn’t allow you to compare two documents for plagiarism.

However, in addition to our Plagiarism Checker, Scribbr also offers an Self-Plagiarism Checker. This is an add-on tool that lets you compare your paper with unpublished or private documents. This way you can rest assured that you haven’t unintentionally plagiarized or self-plagiarized.

Compare two sources for plagiarism

Frequently asked questions: Plagiarism

What is academic integrity?: Academic integrity means being honest, ethical, and thorough in your academic work. To maintain academic integrity, you should avoid misleading your readers about any part of your research and refrain from offenses like plagiarism and contract cheating, which are examples of academic misconduct.
Why is plagiarism wrong?: Plagiarism is a form of theft, since it involves taking the words and ideas of others and passing them off as your own. As such, it’s academically dishonest and can have serious consequences.

Plagiarism also hinders the learning process, obscuring the sources of your ideas and usually resulting in bad writing. Even if you could get away with it, plagiarism harms your own learning.
Does Turnitin check for self-plagiarism?: Most institutions have an internal database of previously submitted student papers. Turnitin can check for self-plagiarism by comparing your paper against this database. If you’ve reused parts of an assignment you already submitted, it will flag any similarities as potential plagiarism.

Online plagiarism checkers don’t have access to your institution’s database, so they can’t detect self-plagiarism of unpublished work. If you’re worried about accidentally self-plagiarizing, you can use Scribbr’s Self-Plagiarism Checker to upload your unpublished documents and check them for similarities.
Can you plagiarize yourself?: Yes, reusing your own work without acknowledgment is considered self-plagiarism. This can range from re-submitting an entire assignment to reusing passages or data from something you’ve turned in previously without citing them.

Self-plagiarism often has the same consequences as other types of plagiarism. If you want to reuse content you wrote in the past, make sure to check your university’s policy or consult your professor.
When do I need to cite myself?: If you are reusing content or data you used in a previous assignment, make sure to cite yourself. You can cite yourself just as you would cite any other source: simply follow the directions for that source type in the citation style you are using.

Keep in mind that reusing your previous work can be considered self-plagiarism, so make sure you ask your professor or consult your university’s handbook before doing so.
Do I have to cite common knowledge?: Common knowledge does not need to be cited. However, you should be extra careful when deciding what counts as common knowledge.

Common knowledge encompasses information that the average educated reader would accept as true without needing the extra validation of a source or citation.

Common knowledge should be widely known, undisputed and easily verified. When in doubt, always cite your sources.
Is plagiarism illegal?: Plagiarism has serious consequences, and can indeed be illegal in certain scenarios.

While most of the time plagiarism in an undergraduate setting is not illegal, plagiarism or self-plagiarism in a professional academic setting can lead to legal action, including copyright infringement and fraud. Many scholarly journals do not allow you to submit the same work to more than one journal, and if you do not credit a co-author, you could be legally defrauding them.

Even if you aren’t breaking the law, plagiarism can seriously impact your academic career. While the exact consequences of plagiarism vary by institution and severity, common consequences include: a lower grade, automatically failing a course, academic suspension or probation, or even expulsion.
Can plagiarism be accidental?: Accidental plagiarism is one of the most common examples of plagiarism. Perhaps you forgot to cite a source, or paraphrased something a bit too closely. Maybe you can’t remember where you got an idea from, and aren’t totally sure if it’s original or not.

These all count as plagiarism, even though you didn’t do it on purpose. When in doubt, make sure you’re citing your sources. Also consider running your work through a plagiarism checker tool prior to submission, which work by using advanced database software to scan for matches between your text and existing texts.

Scribbr’s Plagiarism Checker takes less than 10 minutes and can help you turn in your paper with confidence.
What is self-plagiarism?: Self-plagiarism means recycling work that you’ve previously published or submitted as an assignment. It’s considered academic dishonesty to present something as brand new when you’ve already gotten credit and perhaps feedback for it in the past.

If you want to refer to ideas or data from previous work, be sure to cite yourself.

If you’re concerned that you may have self-plagiarized, Scribbr’s Self-Plagiarism Checker can help you turn in your paper with confidence. It compares your work to unpublished or private documents that you upload, so you can rest assured that you haven’t unintentionally plagiarized.
What is incremental plagiarism?: Incremental plagiarism means inserting quotes, passages, or excerpts from other works into your assignment without properly citing the original source.

Even if the vast majority of the text is yours, including any content that isn’t without citing it is plagiarism.

Consider using a plagiarism checker yourself before submitting your work. Plagiarism checkers work by scanning your document, comparing it to a database of webpages and publications, and highlighting passages that appear similar to other texts.

Scribbr’s Plagiarism Checker takes less than 10 minutes and can help you turn in your paper with confidence.
What is patchwork plagiarism?: Patchwork plagiarism (aka mosaic plagiarism) means copying phrases, passages, or ideas from various existing sources and combining them to create a new text. While this type of plagiarism is more insidious than simply copy-pasting directly from a source, plagiarism checkers like Turnitin’s can still easily detect it.

To avoid plagiarism in any form, remember to cite your sources. Also consider running your work through a plagiarism checker tool prior to submission, which work by using advanced database software to scan for matches between your text and existing texts.

Scribbr’s Plagiarism Checker takes less than 10 minutes and can help you turn in your paper with confidence.
What is verbatim plagiarism?: Verbatim plagiarism means copying text from a source and pasting it directly into your own document without giving proper credit.

Even if you delete a few words or replace them with synonyms, it still counts as verbatim plagiarism.

To use an author’s exact words, quote the original source by putting the copied text in quotation marks and including an in-text citation.

If you’re worried abotu plagiarism, consider running your work through a plagiarism checker tool prior to submission, which work by using advanced database software to scan for matches between your text and existing texts.

Scribbr’s Plagiarism Checker takes less than 10 minutes and can help you turn in your paper with confidence.
What is global plagiarism?: Global plagiarism means taking an entire work written by someone else and passing it off as your own. This can mean getting someone else to write an essay or assignment for you, or submitting a text you found online as your own work.

Global plagiarism is the most serious type of plagiarism because it involves deliberately and directly lying about the authorship of a work. It can have severe consequences.

To ensure you aren’t accidentally plagiarizing, consider running your work through plagiarism checker tool prior to submission. These tools work by using advanced database software to scan for matches between your text and existing texts.

Scribbr’s Plagiarism Checker takes less than 10 minutes and can help you turn in your paper with confidence.
How is plagiarism detected?: Plagiarism can be detected by your professor or readers if the tone, formatting, or style of your text is different in different parts of your paper, or if they’re familiar with the plagiarized source.

Many universities also use plagiarism detection software like Turnitin’s, which compares your text to a large database of other sources, flagging any similarities that come up.

It can be easier than you think to commit plagiarism by accident. Consider using a plagiarism checker prior to submitting your paper to ensure you haven’t missed any citations.
What are some examples of plagiarism?: Some examples of plagiarism include:

Copying and pasting a Wikipedia article into the body of an assignment

Quoting a source without including a citation

Not paraphrasing a source properly, such as maintaining wording too close to the original

Forgetting to cite the source of an idea

The most surefire way to avoid plagiarism is to always cite your sources. When in doubt, cite!

If you’re concerned about plagiarism, consider running your work through a plagiarism checker tool prior to submission. Scribbr’s Plagiarism Checker takes less than 10 minutes and can help you turn in your paper with confidence.
What is plagiarism?: Plagiarism means presenting someone else’s work as your own without giving proper credit to the original author. In academic writing, plagiarism involves using words, ideas, or information from a source without including a citation.

Plagiarism can have serious consequences, even when it’s done accidentally. To avoid plagiarism, it’s important to keep track of your sources and cite them correctly.
What are examples of academic dishonesty?: Academic dishonesty can be intentional or unintentional, ranging from something as simple as claiming to have read something you didn’t to copying your neighbor’s answers on an exam.

You can commit academic dishonesty with the best of intentions, such as helping a friend cheat on a paper. Severe academic dishonesty can include buying a pre-written essay or the answers to a multiple-choice test, or falsifying a medical emergency to avoid taking a final exam.
What are the consequences of academic dishonesty?: Consequences of academic dishonesty depend on the severity of the offense and your institution’s policy. They can range from a warning for a first offense to a failing grade in a course to expulsion from your university.

For those in certain fields, such as nursing, engineering, or lab sciences, not learning fundamentals properly can directly impact the health and safety of others. For those working in academia or research, academic dishonesty impacts your professional reputation, leading others to doubt your future work.
What is academic dishonesty?: Academic dishonesty refers to deceitful or misleading behavior in an academic setting. Academic dishonesty can occur intentionally or unintentionally, and varies in severity.

It can encompass paying for a pre-written essay, cheating on an exam, or committing plagiarism. It can also include helping others cheat, copying a friend’s homework answers, or even pretending to be sick to miss an exam.

Academic dishonesty doesn’t just occur in a classroom setting, but also in research and other academic-adjacent fields.
Is paraphrasing considered plagiarism?: Paraphrasing without crediting the original author is a form of plagiarism, because you’re presenting someone else’s ideas as if they were your own.

However, paraphrasing is not plagiarism if you correctly cite the source. This means including an in-text citation and a full reference, formatted according to your required citation style.

As well as citing, make sure that any paraphrased text is completely rewritten in your own words.
What is the difference between plagiarism and paraphrasing?: Plagiarism means using someone else’s words or ideas and passing them off as your own. Paraphrasing means putting someone else’s ideas in your own words.

So when does paraphrasing count as plagiarism?

Paraphrasing is plagiarism if you don’t properly credit the original author.

Paraphrasing is plagiarism if your text is too close to the original wording (even if you cite the source). If you directly copy a sentence or phrase, you should quote it instead.

Paraphrasing is not plagiarism if you put the author’s ideas completely in your own words and properly cite the source.
Is it plagiarism if you cite the source?: If you’ve properly paraphrased or quoted and correctly cited the source, you are not committing plagiarism.

However, the word correctly is vital. In order to avoid plagiarism, you must adhere to the guidelines of your citation style (e.g. APA or MLA).

You can use the Scribbr Plagiarism Checker to make sure you haven’t missed any citations, while our Citation Checker ensures you’ve properly formatted your citations in APA style.
What happens if you plagiarize?: The consequences of plagiarism vary depending on the type of plagiarism and the context in which it occurs. For example, submitting a whole paper by someone else will have the most severe consequences, while accidental citation errors are considered less serious.

If you’re a student, then you might fail the course, be suspended or expelled, or be obligated to attend a workshop on plagiarism. It depends on whether it’s your first offense or you’ve done it before.

As an academic or professional, plagiarizing seriously damages your reputation. You might also lose your research funding or your job, and you could even face legal consequences for copyright infringement.

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What type of documents does Scribbr proofread?: Scribbr specializes in editing study-related documents. We proofread:

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What plagiarism checker software does Scribbr use?: The Scribbr Plagiarism Checker is powered by elements of Turnitin’s Similarity Checker, namely the plagiarism detection software and the Internet Archive and Premium Scholarly Publications content databases.
Which citation software does Scribbr use?: The Scribbr Citation Generator is developed using the open-source Citation Style Language (CSL) project and Frank Bennett’s citeproc-js. It’s the same technology used by dozens of other popular citation tools, including Mendeley and Zotero.

You can find all the citation styles and locales used in the Scribbr Citation Generator in our publicly accessible repository on Github.