Noplag

Input—per 1M tokens

Output—per 1M tokens

Context—tokens

WeightsClosed

About

Noplag is ranked #1 of 31 in plagiarism checkers on Inferse. 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.

Compared on plagiarism checkers

Free plan: Yesnoplag.com
Paid from: $9.99/monoplag.com
API access: Yesnoplag.com

Facts

Product: Noplag is an open-source plagiarism checker with a hosted cloud service and an engine released under Apache 2.0.noplag.com · 29 Sept 2026
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.noplag.com · 29 Sept 2026
Sources: Its comparison sources include the open web, Common Crawl, Wikipedia, academic indexes, the Noplag Database, and users’ own folders.noplag.com · 29 Sept 2026
Reports: Reports link each match to its source and show a similarity score and exact overlapping text, with PDF export.noplag.com · 29 Sept 2026
Uploads: Users can upload DOCX, PDF, TXT, ODT, or RTF files, paste text, or submit a URL.noplag.com · 29 Sept 2026
Languages: Detection is calibrated at launch for English, Spanish, Portuguese, Polish, and Ukrainian.noplag.com · 29 Sept 2026
AI detection: AI-content detection is marked as coming soon and is intended to appear as a separate signal.noplag.com · 29 Sept 2026
Integrations: The features page lists Canvas, Moodle, Blackboard, and Brightspace integrations via LTI 1.3.noplag.com · 29 Sept 2026
API: The developer API is REST with an OpenAPI spec and webhooks, and is available on paid tiers.noplag.com · 29 Sept 2026
Privacy: Noplag states that submitted documents are not used to train models or shared between accounts, and EU data residency is available.noplag.com · 29 Sept 2026
Security: Noplag says it encrypts data in transit and at rest and does not yet hold formal attestations such as SOC 2.noplag.com · 29 Sept 2026
Retention: Document content is purged 30 days after a free-tier check; paid users can choose a 30-, 60-, or 90-day retention window, while Enterprise can retain it without limit.noplag.com · 29 Sept 2026
Support: Free includes community Discord support, Pro includes email support, and Premium includes priority support with a 12-hour response target.noplag.com · 29 Sept 2026
Limit: Noplag states that its current engine detects verbatim and near-verbatim copying and does not detect paraphrase.noplag.com · 29 Sept 2026
Audience: The pricing page positions Pro for makers and small teams, Premium for agencies and publishers, and Enterprise for universities and regulated organizations.noplag.com · 29 Sept 2026