JPlag

6.7easy start · #18of 31
in Plagiarism Checkers

Free to practise onyes
Free trialno
Well documentedyes
Runs where you workno

Runs on api, Linux, self-hosted.

JPlag is ranked #18 of 31 in plagiarism checkers on The Geeks Club. It runs on API, Linux, Self-hosted. There is a free plan.

JPlag plans and pricing

All plans

JPlag Free Open-source software; runs locally; requires Java SE 25 github.com · 11 Oct 2026

Compared on plagiarism checkers

Web source matching: No
Academic source matching: No
Report export formats: JPlag report (.jplag), CSV
API access: Yes

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The record

Purpose: JPlag finds pairwise similarities among programs to detect source-code plagiarism and collusion.
How it compares: JPlag analyzes program syntax and structure and is designed to find similarities among submitted programs; it does not compare them with the internet.
Typical users: The project says it is typically used to detect copying of student programming exercises and can also identify duplicated or stolen software parts.
Supported languages: The project lists support for Java, C, C++, C#, Python, JavaScript, TypeScript, Go, Kotlin, R, Rust, Swift, Scala, LLVM IR, Scheme, EMF, SCXML, text, and multi-language input.
Run options: JPlag can be run through its command-line interface or called programmatically through its Java API.
Integration: JPlag is available as a dependency from Maven Central for inclusion in Java projects.
Report viewer: Since version 6.0.0, the report viewer is bundled with JPlag and can open generated or existing reports.
Data handling: The project states that analysis runs locally and that source code and plagiarism results are not uploaded or sent externally.
Exclude starter code: A base-code directory can be specified so matches also present in the shared template are ignored.
Sensitivity setting: The minimum matching token length can be adjusted; lower values increase sensitivity but may cause more false positives.
Report limit: The default report shows at most 2500 comparison pairs in its top list and code comparisons, configurable with the -n option.
Requirements: The project README says Java SE 25 is needed to run or build JPlag.
Support: The project directs users to report bugs and issues and provides [email protected] for other inquiries.
Founded: 1996
Price from: Free

Where it ranks on The Geeks Club

Best Plagiarism Checkers in 2026#18 of 31

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Sources

github.com/jplag/JPlag· checked 11 Oct 2026
github.com/jplag/JPlag/wiki· checked 11 Oct 2026
github.com/jplag/JPlag/wiki/1.-How-to-Use-JPlag· checked 11 Oct 2026
jplag.ipd.kit.edu· checked 28 Sept 2026