Noplag Engine

7.9easy start · #2 of 28
in Plagiarism Detection Software

Free to practise onyes
Free trialyes
Well documentedyes
Runs where you workyes

Runs on api, Linux, Mac, self-hosted, Web, Windows. Paid plans from $9.99/mo.

Noplag Engine is ranked #2 of 28 in plagiarism detection software on The Geeks Club. It runs on API, Linux, macOS, Self-hosted, Web, Windows. There is a free plan. A free trial is offered. Paid plans start at $9.99/mo.

Noplag Engine plans and pricing

All plans

Free Free 3 checks per month 2,500 words per check · public web + Common Crawl · self-host for unlimited local checks noplag.com · 29 Sept 2026

Pro $9.99/mo Monthly 50 checks per month · 25,000 words per check · Noplag Database · academic index · REST API + webhooks noplag.com · 29 Sept 2026

Premium $19.99/mo Monthly 200 checks per month · 50,000 words per check · Live Web search · branded PDF reports · priority support noplag.com · 29 Sept 2026

Enterprise Not published Custom Custom check volume · all corpora + Live Web · on-prem or private cloud · SSO/SAML · LMS integrations · dedicated support + SLA noplag.com · 29 Sept 2026

Compared on plagiarism detection software

Free plan: Yes
AI detection: No
LMS integrations: Yes
API access: Yes
Maximum check size: 25,000 words/check

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The record

Purpose: Noplag Engine is an open-source plagiarism detection engine for verbatim and near-verbatim matching against a corpus you control.
Matching: The engine uses winnowing fingerprints to retrieve candidate sources and a seed-and-extend aligner to locate matching character ranges.
Reports: Reports include per-source similarity, matching passage offsets, and coverage accounting.
Detection limits: The engine does not detect paraphrase, semantic similarity, or AI-written text; the README describes those capabilities as roadmap work.
Corpus: The open-source engine searches a local corpus, while the hosted product additionally searches the live web.
Input and ingestion: The engine supports corpus ingestion from .txt, .md, .pdf, and .docx files, including folder ingestion and HTTP file upload.
API: The engine exposes a `/v1` API with checks, reports, uploads, progress events, and corpus management, and ships without authentication.
License and deployment: The engine is licensed under Apache 2.0 and can be run on the user's own hardware with Docker Compose.
Privacy: The maker says submitted documents are never used to train models; hosted-plan retention is configurable and EU data residency is available on request.
Integrations: The Enterprise plan lists Canvas, Moodle, and Blackboard LMS integrations; the features page also names Brightspace via LTI 1.3.
Languages: The hosted product says detection is calibrated for English, Spanish, Portuguese, Polish, and Ukrainian at launch.
Who it serves: The maker positions Free for trying the service or self-hosting, Pro for makers and small teams, Premium for agencies and publishers, and Enterprise for universities and regulated organizations.
Runtime requirements: The repository says development requires Python 3.12 or newer and uses PostgreSQL in its Docker Compose setup.
Founded: 2014
Price from: $9.99/mo

Where it ranks on The Geeks Club

Best Plagiarism Detection Software in 2026#2 of 28

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Sources

github.com/NoplagLabs/noplag-engine· checked 29 Sept 2026
noplag.com/pricing· checked 29 Sept 2026
noplag.com/features· checked 29 Sept 2026