Noplag vs WINNOWR
Noplag
noplag.comWINNOWR
github.comSide by side
| Figure | Noplag | WINNOWR |
|---|---|---|
| Price from | $9.99/mo | — |
| Free plan | Yes | — |
| Free trial | Yes | — |
| Open source | Yes | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 4 | 0 |
| Spec score · Plagiarism Detection Software | 9.1 (#4) | 6.7 (#27) |
| Audience | The pricing page positions Pro for makers and small teams, Premium for agencies and publishers, and Enterprise for universities and regulated organizations. | Longsight presents Winnowr as academic-integrity software for institutions, with a focus on plagiarism detection and reviewable evidence. |
| Company history | Noplag says it launched in Kyiv in 2014, joined a New York EdTech accelerator in 2018 and raised $200,000 in seed funding. | Longsight says Sam Ottenhoff and Scott Siddall founded the company in 2004. |
| Integrations | The features page lists Canvas, Moodle, Blackboard, and Brightspace integrations via LTI 1.3. | The production-style runtime uses SQLite, Cloudflare Queues, and Cloudflare R2. |
| License | Noplag identifies its detection engine as open source under the Apache 2.0 license. | The repository is licensed under GNU AGPLv3. |
| Matching | The live product uses winnowing fingerprints and live-web matching to find verbatim and near-verbatim copying; MinHash LSH and vector reranking are listed as future releases. | It normalizes text, creates word-shingle fingerprints, searches an index for overlap, and fetches likely source pages for evidence. |
| Reports | Reports link each match to its source and show a similarity score and exact overlapping text, with PDF export. | Reports include index overlap, source URLs, and highlighted suspicious spans. |
| Self-hosting | The detection engine can be run with Docker on private infrastructure and has its own API without hosted-service keys. | The project describes itself as understandable and self-hostable, with an on-disk index and local runtime configuration. |
Plans
In their own words
Noplag
Noplag is an open-source plagiarism checker with a hosted cloud service and an engine released under Apache 2.0. Its current matching uses winnowing fingerprints and live-web comparison to find verbatim and near-verbatim copying; it does not detect paraphrase. Sources include the open web, Common Crawl, Wikipedia, academic indexes, the Noplag Database and users’ own folders. Submit DOCX, PDF, TXT, ODT or RTF files, paste text or provide a URL. Reports link matches to their sources, display similarity scores and exact overlapping text, and can be exported as PDFs. Detection is calibrated at launch for English, Spanish, Portuguese, Polish and Ukrainian. AI-content detection is marked as coming soon and intended as a separate signal. The free plan allows three checks per month, up to 2,500 words per check, with community Discord support. Pro costs $9.99 a month and includes 50 monthly checks, up to 25,000 words per check, database and academic-index matching, REST API and webhooks, and email support. A 14-day trial is listed.