Noplag review
An open-source checker with self-hosting, academic matching, APIs, and LMS integrations.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Noplag is a plagiarism checker for students, educators, researchers, publishers, and businesses. It accepts document uploads, pasted text, and URLs, then compares content with live web pages, academic papers, Common Crawl, Wikipedia, and proprietary databases. Reports highlight matching passages, source URLs, similarity scores, and overlapping text, with PDF export. Web, Windows, macOS, Linux, and API access support individual, institutional, and developer workflows. Its open-source Apache 2.0 detection engine and self-hosting support make it particularly relevant to organizations that need control over deployment.
Pricing follows a freemium structure. The Free plan costs $0 per month and includes 3 checks per month, a 2,500-word limit per check, the public web and Common Crawl corpus, and the Apache 2.0 engine with self-hosting. Pro costs $9.99 per month and raises the allowance to 50 checks and 25,000 words per check, while adding the academic index, REST API, and webhooks. Premium costs $19.99 per month for 200 checks, 50,000 words per check, live web search, and branded PDF reports. Enterprise adds custom check volume, on-premises or private-cloud deployment, SSO/SAML, and LMS integrations.
Its ecosystem fit is a strong reason to consider it. LTI 1.3 integrations cover Canvas, Moodle, Blackboard Ultra, and Brightspace, while the API and webhooks support custom applications and workflows. URL submission and PDF reporting also extend it beyond basic document upload. The main trade-off is focus: Noplag currently does not include AI-generated-text detection, and verified checking language coverage is five languages. Choose Noplag when self-hosting, auditable source matching, academic coverage, or institutional integrations matter most. Consider another product if AI detection or broader language coverage is a primary requirement.
Noplag pros and cons
- Where it wins
- Open-source Apache 2.0 engine supports self-hosting
- Checks web, academic, Common Crawl, Wikipedia, and proprietary sources
- REST API, webhooks, and LTI 1.3 LMS integrations
- Where it doesn't
- Verified checking language coverage is limited to five languages
- Free plan allows 3 checks per month with 2,500 words per check
- Does not currently include AI-generated-text detection
Noplag fact sheet, pricing and score →
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