10 of the Best Plagiarism Checker APIs

10 of the Best Plagiarism Checker APIs

Posted in

Almost all academics have to submit a paper at some point in their career, either in college or while pursuing higher education. Plagiarism is an issue that can be very easily avoided. Many universities, companies, and even editors use plagiarism checker APIs to check the originality of the content.

Plagiarism is also an issue that many content creators face. But since manual verification is nearly impossible, it’s best to use a programmatic and automated approach. As a result, its become necessary to use a high-quality plagiarism checker API to ensure that content has no instances of plagiarized text.

Detecting Plagiarism With an API

There are a few different ways to detect plagiarism, but using an API is one of the most effective methods. An API, or application programming interface, can scan a document for signs of plagiarism. This is accomplished by comparing the document to a database of other documents to look for similarities. This method is effective because it can be done automatically and quickly and check for plagiarism across many documents simultaneously. There are many plagiarism checker APIs on the market — let’s review ten of the best ones below.

1. ProWritingAid API V2

The ProWritingAid API is a web-based API that can check for plagiarism in a text. The API uses a variety of algorithms to check for plagiarism. It provides a range of features that can help writers improve their style, grammar, and overall quality of their writing as well. The ProWritingAid API V2 is a valuable tool for writers who want to improve their writing skills.


  • The ProWritingAid API V2 can check for plagiarism in text documents, making it ideal for use in academic or professional settings.
  • The API is easy to use, with a simple API call structure that makes it easy to integrate into existing applications.
  • Language support: ProWritingAid supports all types of English language.
  • Free Version: Yes (500-word count limit).

2. Unicheck

The Unicheck API allows developers to integrate the Unicheck plagiarism checker into their applications. The API provides a set of methods for checking documents for plagiarism and retrieving information about plagiarism incidents. The API is designed to be easy to use. It provides several features that make it a valuable tool for developers who want to add plagiarism checking to their applications.


  • Unicheck can handle bulk files and get plagiarism reports in real-time.
  • Support for OAuth 2.0 protocol.
  • Real-time data sync with webhooks.
  • Language support: Unicheck supports more than 20 languages, including English, Spanish, and French.
  • Free Version: Copyleaks has a free plan, but it’s very limiting.

3. Grammarly for Developers

Grammarly offers an API that can be integrated into various tools and platforms. This makes it easy to check for plagiarism in various contexts. For example, you could use the Grammarly API to check student papers for plagiarism or check content before publication. The Grammarly API is highly accurate and constantly updated to stay ahead of the latest plagiarism trends.


  • API uses natural language processing to analyze a text and identify passages similar to other sources.
  • API can check for plagiarism in various content types, including essays, articles, and research papers.
  • Language support: Grammarly only supports the English language.
  • Free Version: Yes, but to check for plagiarism, you need to have Grammarly premium subscription.

4. Copyleaks

The Copyleaks API solution provides an easy way for any business to integrate our plagiarism detection tool into their platform. It’s fast, secure, and simple to do — not to mention fully customizable. You can decide how it looks and feels and how it sits within your platform. The Copyleaks API solution is widely used in various media, law, and technology industries.


  • Uses the latest AI technology.
  • API integration is fully customizable as per your need.
  • Language support: Copyleaks can scan more than 100 languages, including English, Spanish, French, Portuguese, German, Greek, Chinese, and Japanese.
  • Free Version: Copyleaks has a free plan, but it’s very limiting.

5. SmallSEOTools API

SmallSEOTools is a simple and easy-to-use API that lets you quickly and easily access data to improve your website or blog. The Check Plagiarism method can be used to check plagiarism for an article, post, or document. It will analyze select phrases for plagiarism and respond with the original sources if it detects exact textual copies.


  • API is easy to use and well-documented.
  • Language support: English, Japanese, French, Spanish, Korean, dutch, danish, Swedish, and many more.
  • Free Version: Yes

6. Prepostseo Plagiarism Checker API

Prepostseo Plagiarism Checker API is a simple and powerful API that allows developers to check a given piece of text for plagiarism. The API supports both URL and text-based checking and returns a report detailing the percentage of plagiarism and a list of sources of the text that was copied. It can run plagiarism checks on individual sentences or complete articles.


  • Supports multiple platforms with easy configuration.
  • Secure: Does not store data in their database.
  • Fast and accurate checking for .doc, .txt, and .docx document types.
  • Multiple language support: French, Dutch, Spanish, and many other languages.
  • Offers limited free use.

7. Copyscape Premium API

The Copyscape Premium API allows you to easily integrate plagiarism into your internal systems. This enables content editors to quickly vet the originality of new text and enables large-scale checks for offline content. If you use WordPress, then Copyscape also has a plugin that lets you use your API credentials to integrate Copyscape Premium into your WordPress workflow seamlessly.


  • Service and receive results in JSON, XML, or HTML format.
  • Supports having a private index.
  • Language support: Support all kinds of common language except those that use ideograms.
  • Free Version: Copyscape starts at 3 cents per search up to 200 words, and 1 cent per 100 words after that.

8. Plagium API

The Plagium API is a powerful tool for anyone who needs to analyze a text document. It can identify similar documents and calculate a score for each match. The Plagium API can also compare and rank two text documents.


  • Send and receive results in JSON, XML, or HTML format.
  • Support privet index.
  • Language support: English, French, Portuguese, and Spanish.
  • Free Version: Plaguim also does not have any free tier.

9. plagly API

The plagly API is a powerful tool that can help you check for plagiarism in your content. With this API, you can submit a piece of content and get a report detailing any plagiarism instances. This report includes information on where the plagiarized content was found, as well as the source of the content. You can also use the plagly API to check for plagiarism in multiple pieces of content at once, making it a valuable tool for content creators and publishers.


  • Gives you side by side comparison of the results.
  • Very accurate.
  • Language support: Not defined.
  • Free Version: Yes.

10. PlagScan API by Turnitin

The PlagScan API is based on a RESTful architecture. The API can be used to build an application that uses PlagScan as a service. You can also use it to integrate PlagScan with third-party platforms like SharePoint, Blackboard, or Moodle. The API provides easy access to both administrative and user tasks.


  • Multiple language support: detect plagiarism in any language that uses international UTF-8 encoding.
  • Free Version: Plegscan also does not have any free tier.

Final Words

A plagiarism checker tool is useful for educational institutions, business marketing initiatives, or news sites. Above, we’ve reviewed some of the best plagiarism checker APIs you can use within your applications. With this knowledge, developers can use their computer programming skills to ensure content is original and free from plagiarism issues.