How to check plagiarism pdf file free online 2021

Plagiarism is one of the top problems on the internet. Internet has made it easier to get access to information but because of it, plagiarism has taken a rise as well.

In this article we will explain how to check plagiarism online in pdf 2021.

There are different tools online which help you check plagiarism.

But before you move to them, you need to understand what plagiarism is and how does a plagiarism checker work.

Working of plagiarism checkers

Every time you upload your text online to check plagiarism for free, the plagiarism checkers start comparing the text with the text available online.

The text can be either identical to the text you have written or similar to it.

Even if you had the same idea as someone or tried to get inspiration from someone else, the plagiarism checker will detect the websites or the articles easily.

They will not just show you the content that has been plagiarized, but the percent of the plagiarized content from a single website.

There are different kinds of content that can be plagiarized, such as:

Academic content

Academic content can include your assignments, essays, the short stories or anything else.

The plagiarism checkers will check plagiarism online on different websites and some offline data.

Since the academic content is different from the regular content like the articles, blogs, web content, etc.

There are some specific academic writing plagiarism checkers that also check your content by comparing it to the assignments of other students.

A lot of teachers are using those tools these days and to be safe side, it is preferable to check plagiarism for free on these tools and know whether you are on the safe side or not.


The articles being published on the internet have to be unique and a personal work instead of some stolen words.

All of the search engines penalize the websites using any kind of plagiarized content.

This can be purely accidental. For example, if you are writing down a list of “how to earn money online”, there are a lot of ways that will overlap.

The plagiarism checker tools can mistake it for plagiarism and can punish you.

You can avoid this if you check the plagiarism in time and change the wordings a little bit.

There are thousands of articles written on almost every genre and it is not the writer’s fault to have the same ideas as someone else.

When check plagiarism online, the tool will compare the text with all the online sources and give you the results. There are ways to avoid it such as:

  • Managing your citation. The plagiarism checking tools have been made smart but there are times when they might start showing your citations as plagiarized content. You need to manage your citations correctly to avoid that.
  • Rephrase the sentences: If the whole line is being marked as plagiarized, you can rephrase the sentence and make it simpler or to your advantage. Change the words a little bit or convert the active voice into passive and vice versa.
  • Using synonyms: There are points where you are unable to change the whole line as they do come in the same order. You can try using synonyms at such points to try to get out of plagiarism.
  • Paraphrase the content: If you are unable to work on your own and must copy someone else’s work, the smart way to do it by paraphrasing it. You can try reading the content once, understanding it and writing it in your own words.

Plagiarism checker for pdf

A plagiarism checker for pdf mostly works the same way it does for a word document with a few changes.

You upload the file in the same way, it will compare the text in the same way and will show you the results.

The most basic change is the file form. The text inside the pdf file can be in the form of text now or it can be in the form of images. Once you upload the file, the first step is finding out the kind of text in the file.

If it is in a soft written form, the text will be worked on in the identical way as in word. If the text is not in the soft written form, the tool will use the OCR to detect the content.

When you are looking for the ideal plagiarism checker for pdf, make sure you pick the one with OCR. A lot of pdf files do not contain any text but are consisted of just images with text.

The images can be translated by using an OCR tool deployed in most of the plagiarism checkers. If it is not deployed, you can have problems later while you are trying to check the whole text for plagiarism.

It would not make sense to type the whole text out yourself so you can just use an OCR friendly tool.

Why is it important to check plagiarism?

Plagiarism is a one of the major problems on the internet and in the literacy department. Words, lines, quotes and ideas are stolen too easily by people.

While one person said it, someone else can be wowed for it.

A plagiarism checker eradicates that problem from the society so everyone can have their original content. Once the content is detected with plagiarism, there are serious consequences followed by it.

Some of them are:

  • Loss of reputation
  • Loss of money
  • Getting fired
  • Getting expelled
  • Getting fined
  • Legal consequences


It is smart to use a plagiarism checker beforehand to avoid any of the consequences given above. Before you claim your piece of writing, make sure it is originally yours and someone else has not already claimed it to their name.

There are many free plagiarism checkers online that you can try to get started with like PREPOSTSEO. If you want, you can upgrade to their premium versions of keep using them the way they are.