Copyscape vs JPlag
Copyscape
copyscape.comJPlag
github.comSide by side
| Figure | Copyscape | JPlag |
|---|---|---|
| Price from | $4.95/mo | Free |
| Free plan | Yes | Yes |
| Free trial | Yes | — |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 5 | 2 |
| Spec score · Plagiarism Detection Software | 9.2 (#2) | 8.8 (#9) |
| Documentation and support | GetApp lists FAQs/forum, a knowledge base and email/help-desk support options. | Documentation is provided through the GitHub wiki, repository README, issue tracker, discussions and a listed project email address. |
| Founded | Crunchbase lists the company as founded in 2003. | 1996 |
| Integration | Copyscape provides a WordPress plugin for integrating Premium checks into a WordPress workflow. | JPlag is published on Maven Central for inclusion as a dependency in Java projects. |
| Purpose | Copyscape checks web content and new human- or AI-generated content for plagiarism and duplicate text found online. | JPlag finds pairwise similarities among programs to detect source-code plagiarism and collusion. |
| Support | Copyscape accepts questions, comments, and suggestions through its contact form. | The project directs users to report bugs and issues on GitHub and provides a Q&A discussion section. |
| What it does | Copyscape searches online content for matching or copied text and supports originality checking for human- and AI-generated material. | JPlag compares programs pairwise to identify likely source-code plagiarism and collusion. |
Plans
Copyscape
- Free CopyscapeFree
- Copyscape Premium$0.03, paid once
- Copysentry Weekly protection$4.95 a month
- Copysentry Premium daily protection$19.95 a month
- Copyscape EnterprisePriced on request
In their own words
Copyscape
Copyscape checks web pages and newly written human- or AI-generated content for plagiarism and duplicate text found online. Its free checker scans a URL and presents a word-by-word comparison of results, but shows no more than 10 search results and limits scans per website. Premium accepts pasted text as well as PDF and Word uploads for originality checks. Its Batch Search can process up to 10,000 pages in one operation, with each page billed like a regular search. The Premium API can automate plagiarism and AI checks and return results in JSON, XML, or HTML; a WordPress plugin supports checks in a WordPress workflow. Premium users can create a private index of their own content, accessible only through their Copyscape account. Copysentry monitors selected pages daily or weekly and emails alerts when it finds copies. Enterprise can be hosted on-premises or in a private cloud. Copyscape says it uses Google for search and then processes results with proprietary algorithms. It warns that AI detector results may misclassify human or AI text and should not be the sole basis for disciplinary action.
JPlag
JPlag is free software for finding pairwise similarities among programs that may indicate source-code plagiarism or collusion. It examines programming-language syntax and program structure, helping identify overlap even when code has been partly obfuscated. Analysis runs locally on the user’s machine, and the project says no data is sent externally. Comparisons are between submitted programs rather than internet sources. Listed language support includes Java, C, C++, C#, Python, JavaScript, TypeScript, Go, Kotlin, R, Rust, Swift, Scala, LLVM IR, Scheme, EMF, SCXML, text, and multi-language submissions, with varying maturity. Users can run the command-line interface or Java API, launch a report viewer from the CLI, or add JPlag through Maven Central. Reports show at most 2,500 pairs by default, adjustable with the -n option. Lower minimum matching-token lengths increase sensitivity but can also increase false positives. Running or building requires Java SE 25.