Dolos vs Fallow

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.

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