JPlag vs Turnitin Similarity

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.

Turnitin Similarity has no write-up on Specifiction yet; its figures are above.