Check-Plagiarism vs Noplag
Check-Plagiarism
check-plagiarism.com
Noplag
noplag.comSide by side
| Figure | Check-Plagiarism | Noplag |
|---|---|---|
| Price from | $4.17/mo | $9.99/mo |
| Free plan | — | Yes |
| Free trial | — | Yes |
| Open source | — | Yes |
| Web | Yes | Yes |
| Windows | — | Yes |
| macOS | — | Yes |
| Linux | — | Yes |
| Android | Yes | — |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 10 | 4 |
| Spec score · AI Plagiarism Checkers | 8.7 (#7) | 9.2 (#3) |
| Input methods | Users can paste or type text, or upload DOC, DOCX, TXT, or PDF files for checking. | Users can paste text, upload DOCX/PDF/TXT/ODT/RTF files or submit a URL for checking. |
| Integrations | The API page says the API can integrate with any CMS and names WordPress, widgets, and Android among supported platforms. | The features page lists Canvas, Moodle, Blackboard, and Brightspace integrations via LTI 1.3. |
| Languages | The checker page claims support for over 20 languages. | Detection is calibrated at launch for English, Spanish, Portuguese, Polish, and Ukrainian. |
| Rating on Capterra | 4.5 out of 5 from 2 reviews | 1.0 out of 5 from 1 review |
| Rating on G2 | 4.5 out of 5 from 13 reviews | 4.2 out of 5 from 12 reviews |
| Reports | Users can save, download and share detailed plagiarism reports, including PDF output. | Reports link each match to its source and show a similarity score and exact overlapping text, with PDF export. |
| Support | The API page advertises 24/7 support for selected API tiers and offers contact for integration questions. | Free includes community Discord support, Pro includes email support, and Premium includes priority support with a 12-hour response target. |
| What it does | The service checks submitted text against web, academic and publication sources and reports duplicated passages, similarity percentages and matching sources. | Noplag checks submitted text or files for plagiarism and returns similarity scores, highlighted overlaps and source links. |
Plans
Check-Plagiarism
- Weekly$4.99, paid once
- Annual$8.33 a month
- API Basic$10 a month
- API Company$14.99 a month
- Monthly$14.99 a month
- Semi-Annual$16.66 a month
- API Basic Yearly Plan$50 a year
- API Business$50 a month
- API Company / Webmasters$99.99 a year
- API Business / Colleges / Universities$250 a year
In their own words
Check-Plagiarism
Check-Plagiarism is a plagiarism-checking service for students, teachers, researchers, content creators, and digital publishers. It accepts pasted or typed text and DOC, DOCX, TXT, or PDF uploads, with a listed maximum of 7,000 words per document. The checker reports duplicated passages, sentence-level matches, similarity percentages, and matching sources. Its AI is described as detecting paraphrased or lightly edited text as well as exact matches. The service says it checks billions of web pages and provides access to academic databases and publications, with support claimed for more than 20 languages. Reports can be downloaded or shared, including as PDF. Free online use is available with limited searches; registered accounts can increase the limit. Plans include Monthly at $14.99 a month and Annual at $8.33 a month, billed $99.99 every 12 months. API access and LMS integrations are listed.
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.