Dolos
Dolos: A free, developer-focused checker for source-code similarity, with web, API, CLI, and self-hosting. Ranked #29 of 31 in Plagiarism Checkers by our editors (6.4/10); pricing: Free plan; best for developers wanting open-source code checking.
At a glance
- Editor score6.4 / 10
- PricingFree plan
- Best forDevelopers wanting open-source code checking
- Free planYes
- Paid fromFree
- Web source matchingNo
- Facts checked21 Sep 2026
Where it wins
- Free and open-source with web, API, CLI, and self-hosting options
- Interactive similarity visualizations with configurable thresholds
- JSON, CSV, Docker Compose, JavaScript, and Dodona integration
Where it doesn't
- Focused on source code, not ordinary text, web pages, or scholarly publications
- Requires programming-language submissions packaged as ZIP files for web analysis
- Its breadth is narrower than general-purpose plagiarism checkers
Our verdict on Dolos
Dolos is an open-source source-code plagiarism detection tool developed by Team Dodona at Ghent University. It is designed primarily for teachers, programming courses, and developers who need to compare programming exercises. Users can upload ZIP files through the web application, while automatic programming-language detection supports analysis across multiple languages through Tree-sitter parsers. The core output is a similarity report with interactive visualizations, making Dolos a focused fit for programming assignments rather than general written content.
Its strongest advantage is the range of ways to fit source-code checking into a workflow. The web application supports ZIP-file submissions and interactive reports, while the JSON API supports automated submissions and CSV exports provide report data. Developers can also work offline through the command-line interface, integrate the JavaScript library, or run Dolos themselves with Docker Compose. Metadata support for submissions adds useful structure for course and assignment workflows, and Dodona integration connects it with that platform.
Dolos is free and open source, with no paid tier structure to weigh between feature levels. That makes it well suited to teams that want control over deployment, offline analysis, or integration details. Its limits are equally clear: URL checking is not part of its scope, and the product is built around source-code similarity rather than ordinary text, web pages, or scholarly publications. Choose Dolos for programming-course workflows and developer-led automation; choose a different category of checker for essays, webpages, or broader publication screening.
Your product? Our editors can test Dolos in depth and publish a review, labelled as paid · from $149/mo →
Dolos pricing
Dolos fact sheet
| Free plan | Yes |
|---|---|
| Paid from | Free |
| Web source matching | No |
| Academic source matching | No |
| Supported languages | Not verified |
| Word limit | Not verified |
| Report export formats | CSV |
| API access | Yes |
| LMS integration | Not verified |
| Deployment | Cloud, Self-hosted |
| Platforms | Web, Windows, Linux |
| Support | Docs |
| Built for | Small business, Mid-market, Enterprise (editorial estimate) |
| Integrations | 1 integrations: Dodona |
| Pricing | Free plan |
| Website | dolos.ugent.be |
| Facts checked | 21 Sep 2026 |
Dolos integrations
Dolos lists 1 integrations on its own site.
- Dodona
Alternatives to Dolos
- Turnitin AI Writing DetectionA focused institutional tool for identifying text that may be AI-generated or modified.9.4
- Crossref Similarity CheckA focused manuscript-screening service with academic matching, reports, filters, and API access.9.2
- iThenticateA paid similarity checker built for researchers, publishers, and private repositories.9.0
Also Ranked In
Dolos is ranked in 3 of our directories.
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Featured on iTechGuides
Dolos is listed in our Plagiarism Checkers directory. Add the badge to your site — it links back to this page.
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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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