The Five Top Free and Paid Plagiarism Checkers

plagiarism checkers

If you want to be absolutely sure that your content is original and that it won’t harm your search ranking, then you’ll need to make use of plagiarism checkers.

Plagiarism in your content can quickly derail your otherwise strong Search Engine Optimization (SEO) strategy, and it isn’t always done intentionally. If you’re writing your own content; you may have researched a few articles that you found valuable, and you could have subconsciously carried over some of the key phrases from this content. Taking and repurposing ideas and high level concepts is not uncommon and is a widely used technique in marketing, and Google won’t penalize you if your content is unique.

The problem arises when your content is too similar, word for word and phrase for phrase. If you buy content from a third party, particularly from a blog articles service that doesn’t have a good reputation, then you may find that content has been stolen, or spun in a way that is not unique.

How do Plagiarism Checkers Work?

Software used for checking plagiarism works similarly to a search engine. Instead of looking for short search terms, a specialized piece of software will crawl the web for the long form content that you provide. It will look at individual words, paragraphs, headings, and key phrases.

When Google looks at content for determining search ranking, the algorithm doesn’t just look at the content itself. It will also view structure. Tips articles that follow the same layout with similar headings and points in the exact same order will often be considered duplicate, and Google will rank the oldest page first.

It goes without saying that your content needs to be unique. This doesn’t just help with your search ranking, but it also ensures that you provide your audience with fresh and interesting information, even if it covers a familiar topic.

Any time that you are self-publishing content, even if you’ve written it yourself, it pays to use plagiarism checkers. Here are five solutions currently available, including free and paid options that can help you to ensure that your content is unique.


This option is a completely free plagiarism checker that is popular with webmasters and SEO professionals. While Quetext can be effective at detecting plagiarism in articles, it’s not the fastest solution available, which can make it inconvenient if you need to check content regularly, or if you need to check a batch of files in quick succession. Quetext can sometimes take up to five minutes to complete a plagiarism search, depending on the length of the content that is provided.

On the plus side, this is an incredibly easy tool to use where you only need to paste in your text, and there is no registration necessary. This is useful for one-off plagiarism checks, but we don’t recommend this software for professional or regular use.


DupliChecker is similar to Quetext in the way that it is slow to respond to searches, and can take up to 30 seconds to search for duplicates from a 500-word article. Despite not being the fastest, it has the benefit of being free, and the online software supports uploading of .docx and standard .txt files.

One area where DupliChecker lags behind Quetext is with the search limitation. There’s a 1000-word limit and only one search can be performed daily by free users.

This can be a useful tool if you don’t have access to paid plagiarism checkers and don’t frequently need to check articles and other web content. For professional use, the results are too slow to be feasible and the search limitation will be a deal breaker.


Unicheck is another free option, this time allowing for up to three searches of 500-words per day. Although marketed primarily at academic users, this plagiarism checker does look at general online sources, so is useful for bloggers, article writers, and webmasters. As a free tool this outperforms Quetext and Duplichecker because it provides results faster. As a professional tool, premium access is reasonable and it will cost $15 USD for up to 100 pages of 500-word text.

Unicheck provides detailed reports and comparisons when duplicate content/plagiarism is found, helping you to change your wording or rewrite content.

Viper Plagiarism Checker

Viper is another solution aimed at academic users, however, a number of professional writers and webmasters do use this service, particularly if their content relates to scientific research or other fields where published papers and journals are common. Viper uses a proprietary search method to compare against 10 billion sources that include academic sources and general web sources.

Viper can find plagiarism for highly specialized and technical documents, whereas some free plagiarism checkers would not. Viper is pricey, but it can be good value if you do need a checker that crawls through less common academic sources. A single credit for up to 5000 words will cost the equivalent of $4 USD.


Copyscape is by far the most popular plagiarism checker used by professional content writers, blog writers, webmasters, SEO professionals, and content creation services. Copyscape runs quickly and can deliver results within seconds. It also has helpful features for professionals, including one that will allow you to save examples of your existing content so that you can check future content against your own database. This is useful to ensure that you haven’t unintentionally written content that is too similar to your previous articles.

All plagiarism tools can detect false positives, but the way that Copyscape delivers results will allow you to identify these easily. It provides a single results page with all examples of similar or duplicate text, so that you can manually determine whether to push forward with your content or not. Common words and phrases can sometimes trigger plagiarism checkers, even when the content is over 80% unique.

Copyscape is not a free service but prices are highly affordable, with searches up to 200 words charged at $0.03, and each additional 100 words charged at $0.01. The accuracy, ease of use, and helpful features of Copyscape have kept it as the industry standard for more than ten years.

Don’t Take Risks When You Are Outsourcing Your Content Writing

If you’re paying someone else to write your articles, then you’ll need to be sure that a plagiarism checker has been used. Running your own checks will cost you time and money when you use the better featured paid solutions, and if you do discover plagiarism, you’ll need to go back to your writers, delaying the publication of your content.

At Low Price Articles, we know that your time is valuable and that you expect convenience when you pay for a writing service. We produce only unique content, and never spin existing content unless you specifically ask us to. Even when we do repurpose an existing idea at your request, our content is never a carbon copy and it always adds new value.

We rely on Copyscape Premium because it is the fastest, most accurate, and most reliable paid plagiarism checker. We guarantee that every article we produce is unique and written to your specifications. If you’re tired of the same old uninspired, recycled, or even plagiarized content, then it’s time to talk to an article writing team that you can trust.

Contact us today or start ordering right away from a professional team with low article prices and no membership fees.