Top 10 Plagiarism Checkers to Detect Copy-Paste Text in 2025

The issue of plagiarism is at the heart of concerns, especially in this digital age, when information is abundant and easily accessible. Authors are thus faced with a major challenge: preserving the originality of their work. For this, they use plagiarism checkers, which is essential for detecting copy-pasted texts. Are you a student, professional writer, or researcher looking for a powerful tool? 

The 10 Best Plagiarism Checkers Solutions of the Moment: 

Scribbr

A popular anti-plagiarism site, Scribbr offers a range of advanced features for reporting plagiarism in academic papers. It uses text comparison technology to spot similarities between online sources and internal data.

This tool has the advantage of being very accurate since it even detects paraphrases. Its ease of use and user-friendly interface make it a very popular tool for many people.

Scribbr’s main drawback, however, is its relatively high cost. Monthly subscriptions start at $90.95, and annual subscriptions are discounted.

Quetext

Quetext plagiarism checker software stands out due to its ease of use and powerful features.  It allows you to detect plagiarized content by comparing documents to a large database and online sources.

The main advantage of this tool is its ability to generate detailed reports highlighting suspected plagiarism and potential sources. Quetext also has a built-in citation option and several support solutions.

As a disadvantage, processing times are sometimes long for large documents. In addition, it is not very effective in detecting plagiarism in scientific articles.

Quetext is available in a free version (up to 2,500 words) and a paid version (up to 25,000 words). The price of the monthly subscription starts from $15.99.

Grammarly

Grammarly is an anti-plagiarism software that offers many features. Among others is correcting grammatical, spelling and punctuation errors, plagiarism checking, tone optimization… The tool uses sophisticated algorithms to perform the plagiarism test and suggest real-time corrections.

Grammarly has several advantages,s such as:

• seamless integration with various platforms (browsers, applications, word processors, etc.),
• displaying the actual source of plagiarism,
• the availability of a language and citation support tool …

Some drawbacks to Grammarly include a 100,000-character limit and interesting features accessible only with a premium subscription (starting at $12 per month ).

UniCheck

UniCheck is a plagiarism checker software known for detecting copied content. It compares your text with a large database containing academic documents, online publications and previous works. Its main advantage is its high accuracy.

UniCheck not only identifies the original source of plagiarized content but also finds others that contain small parts of the copied texts.

The  plagiarism checker also has some drawbacks:

• It sometimes tends to provide multiple matches for the same plagiarized sentence and its relationship is unclear.
• Subscription prices vary depending on the volume of text submitted.

PlagScan

PlagScan is a plagiarism detector that enjoys a good reputation because of its efficiency and ease of use. When you run an analysis, the tool brings up the copied passages and highlights them in different colors, depending on the level of plagiarism risk. It then presents you with the real sources of plagiarism.

PlagScan’s reports make it easier for you to understand the detection results. On the downside, the tool does not offer detailed assistance and sometimes highlights sources with similar colors.

As for the subscription price, it starts from $4.99 for the first 5,000 words.

PrePostSEO

A very handy tool for plagiarism checking, PrePostSEO works quite similarly to the other anti-plagiarism software on this list. PrePostSEO compares your documents with a large database.

It displays search results in just a few minutes. Another advantage of this tool is its smooth interface, allowing you to submit texts easily and clearly understand the results.

PrePostSEO is also available in a free version (1,000 maximum per search) and a paid version. The subscription price for the latter is between $10 per month.

PlagiarismDetector

PlagiarismDetector was designed to detect copy-pasted texts in academic and professional documents.

This free tool allows you to analyze up to 1,000 words per search. If you want to analyze a longer text, you will have to pay a subscription of $19.99 for 30,000 words or 100 pages. This will allow you to enjoy more advanced features and much more in-depth analyses.

CopyScape

For detecting copied content online,  CopyScape is one of the most widely used online plagiarism checking tools. It compares your submitted text with millions of indexed web pages, helping to identify similarities and potential duplications.  

To analyze content with CopyScape, you just need to copy and paste the text or enter a URL directly, which works like search engines for plagiarism. This anti-plagiarism software offers many features such as free control, API, Copysentry protection system…

To get the premium version and all its benefits, you will need to pay $0.03 for the first 400 words, then $0.01 for each subsequent 100 words.

Compilation

Compilatio is an anti-plagiarism software designed especially for pupils, students and doctoral students. It allows them to prevent plagiarism in academic documents (internship reports, dissertations, theses, etc.) and professional documents.

The detector has an extensive database containing online sources and digital documents deposited by educational institutions (previous works). Compilatio is known for its effectiveness in checking plagiarism. It displays the percentage of duplicate text and the different sources detected.

This plagiarism checker offers several subscriptions, which vary depending on the needs and volume of text to be analyzed.

Copyleaks

Copyleaks is a powerful plagiarism detector. It is able to highlight direct duplications, paraphrases as well as translations. The anti-plagiarism tool provides you with a detailed report of the detection results. Moreover, you have the option to download the files in different formats for a quick and accurate analysis.

In addition to the anti-plagiarism software in this top 10, Copyleaks integrates artificial intelligence. This allows it to adapt to all types of texts.

It offers 20 free scans per month. To continue the plagiarism test after using these, you must make a subscription whose price starts at $8.33.

How does software that detects copy-pasted texts work?

Copy-paste detection software, also known as plagiarism detection software, uses sophisticated algorithms to compare and analyze documents to identify similarities. Here’s how such software typically works:

1. Source Document Collection: Detectors collect a lot of data from source documents, including academic articles, books, websites, online publications, and other publicly available content.
2. Indexing: Source documents are indexed and processed to facilitate rapid searches. This allows the software to compare the submitted document with thousands or even millions of similar texts relatively quickly.
3. Analysis of submitted content: When a user submits a document to the software, it breaks the text into smaller sentences or blocks of text, which are then compared to the indexed source documents.
4. Comparison algorithm: Tools of this type use a comparison algorithm to assess the similarity between sentences or blocks of text in the submitted document and the source documents. Different techniques can be used for this, such as string comparison, lexical and syntactic analysis, and natural language processing (NLP) techniques.
5. Reporting: Once the analysis is complete, users can access a report showing which parts of the submitted document match existing content in the database. The report also shows the similarity percentage between the submitted document and the identified sources.
6. Sensitivity control: Some plagiarism checkers allow users to adjust the detection sensitivity. This can help filter out minor or common similarities, focusing on more significant matches.

Copy-paste detection software does not provide a definitive judgment about the presence of plagiarism in a document. Rather, it guides users and institutions to alert them to parts of the content that require further review. The final judgment about plagiarism often remains at the discretion of instructors, editors, or content managers.

What are the anti-plagiarism tools most used by universities?

Universities’ most popular plagiarism checkers are Turnitin, Compilatio, Urkund, Copyscape, and Grammarly. These tools play a vital role in preserving academic integrity by identifying potential similarities between documents and helping prevent plagiarism.

What tools are most used to detect duplicate website content (SEO)? 

The most commonly used plagiarism tools for reporting duplicate content on websites (SEO) are Copyscape, Siteliner, Screaming Frog, and Grammarly. These tools help identify duplicate or copied content on the Internet, which is crucial for maintaining a good online reputation and avoiding search engine penalties.

Are there any tools that spot AI-generated content (ChatGPT)? 

Yes, the most powerful detectors to date for detecting English content generated by AI (like ChatGPT) are Lucide AI and  Winston AI.