Dolos vs PMD
Dolos
dolos.ugent.bePMD
pmd.github.ioSide by side
| Figure | Dolos | PMD |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | Yes | — |
| Web | Yes | — |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | Yes | — |
| Self-hosted | Yes | Yes |
| Plans published | 2 | 1 |
| Spec score · Code Duplication Detection Tools | 8.7 (#1) | 8.1 (#4) |
| Languages | Dolos uses Tree-sitter parsers and supports common languages including Bash, C, C++, C#, Elm, JavaScript, Java, PHP, Python, and TypeScript out of the box. | PMD focuses mainly on Java and Apex and supports 16 other languages, including JavaScript, Kotlin, Swift, and XML. |
| Purpose | Dolos detects plagiarism by finding similarities between source code submissions. | PMD is an extensible cross-language static code analyzer that finds common programming flaws. |
| Support | General questions and support are handled through GitHub discussions, while bugs and feature requests use GitHub issues. | The project directs users to Stack Overflow for questions, GitHub issues for suspected bugs or requests, and Gitter for quick questions. |
| Usage | The web app accepts a ZIP of source files and automatically detects languages from file extensions, analyzing only the dominant language in mixed-language ZIPs unless a language is selected. | PMD provides a command-line interface for checking source directories against a ruleset. |
Plans
In their own words
Dolos
Dolos is a free, open-source tool for finding similarities between source-code submissions, particularly for teachers reviewing tests, exams, and exercises where collaboration may be allowed in small groups. Its analysis process tokenizes files, fingerprints token sequences, indexes matches, and produces reports. For each file pair, reports include similarity, total overlap, and the longest matching fragment. Dolos uses Tree-sitter parsers and supports languages including Bash, C, C++, C#, Elm, JavaScript, Java, PHP, Python, and TypeScript. The web app accepts ZIP files and detects languages from file extensions; in mixed-language archives, it analyzes only the dominant language unless a language is selected. Its public API accepts ZIP submissions up to 10 MB, with the CLI or library recommended for larger submissions. Analyses can also run locally, with results displayed in a browser, or on a self-hosted server. The free web app is hosted on Ghent University servers in Belgium. Dolos provides a JSON API for integrations such as Dodona and lists CSV as a report export format.
PMD
PMD is a free, extensible static code analyzer that checks source code for programming flaws such as unused variables, empty catch blocks, and unnecessary object creation. It includes more than 400 built-in rules, and teams can write custom rules in Java or XPath. Its bundled CPD tool finds duplicated code across many programming languages. PMD checks source directories from the command line and can run as a Maven, Ant, Gradle, or bld build operation. Supported languages include Java, JavaScript, Salesforce Apex and Visualforce, Kotlin, Swift, Modelica, PL/SQL, Apache Velocity, JSP, WSDL, Maven POM, HTML, XML, and XSL; Scala is supported without Scala rules. It runs on Linux, macOS, and Windows and requires Java 8 or above. For CI, its GitHub Action can create SARIF reports and fail builds based on violation counts; documentation also covers GitLab, Jenkins, and Bamboo integrations. IDE integrations include Eclipse, IntelliJ IDEA, and Visual Studio Code, though some listed plugins are not actively maintained. Only the latest major version is actively developed.