# jplag/JPlag

State-of-the-Art Source Code Plagiarism & Collusion Detection. Check for plagiarism in a set of programs.

Repository: https://github.com/jplag/JPlag
Canonical: https://ross.abutalabs.com/products/jplag
Homepage: https://jplag.de
Language: Java
License: GPL-3.0
License Family: copyleft
Topics: plagiarism-detection, collusion-detection, plagiarism-check, plagiarism-prevention, source-code-analysis, software-plagiarism, plagiarism, source-code-plagiarism, academic-dishonesty, code-similarity, cs-education, education, online-learning, plagiarism-checker, program-analysis, programming-education, plagiarism-checking, plagiarism-detector, moss
Last push: 2026-08-26T13:25:53+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 36, longevity 100
- inputs: {"age_days": 4183, "days_push": 7, "days_rel": 265, "gap_med": 97, "n_releases_24m": 4}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1939, forks 376 (observed 2026-08-28T04:05:57.291345+00:00)

## What it is
JPlag is a Java-based tool that detects plagiarism and collusion in sets of source code programs by computing pairwise similarities locally. It supports many programming languages and works even on obfuscated code without uploading any source code online.

## Use cases
- detect plagiarism in student programming assignments
- check if two codebases are similar
- find collusion among students in a programming course
- compare source code similarity offline without uploading code
- detect obfuscated code copying
- check submissions for academic dishonesty

## When to choose
- grading programming assignments in CS education
- you need local, privacy-preserving similarity analysis
- you need support for many programming languages
- you need to detect obfuscated plagiarism

## When to avoid
- you need a hosted plagiarism service with a web UI
- you need natural-language text plagiarism detection
- you need real-time code similarity checking in an IDE

## Facets
- artifact type: cli-tool
- maturity: active
- function: parser, developer-tools, search-engine
- domain: education, developer-tools, programming-languages, security
- platform: jvm, cli, cross-platform
- tags: plagiarism-detection, code-similarity, academic-integrity, collusion-detection, source-code-analysis

## Member repositories
- jplag/JPlag (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:57.291345+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:08:11.580436+00:00, confidence not recorded.
  - readme: https://github.com/jplag/JPlag (fetched 2026-08-28T04:05:57.291345+00:00, sha 980a0fb671ce)
  - homepage: https://jplag.de (fetched 2026-08-29T10:47:29.210010+00:00, sha 3a5537f1077e)
- Data as of 2026-08-30T08:39:29.467469+00:00.