Noplag Engine vs Pangram

Noplag Engine is an open-source plagiarism detection tool that checks text for verbatim and near-verbatim matches against a corpus you control. It uses winnowing fingerprints to find candidate sources, then aligns matching character ranges. Reports show similarity by source, passage offsets, and coverage accounting. It accepts.txt,.md,.pdf, and.docx files, with folder ingestion and HTTP uploads, and exposes a /v1 API for checks, reports, uploads, progress events, and corpus management. The API ships without authentication. The open-source engine searches a local corpus; the hosted product also searches the live web. It does not detect paraphrase, semantic similarity, or AI-written text. The engine can run on your own hardware with Docker Compose under the Apache 2.0 license. The repository lists Python 3.12 or newer for development and PostgreSQL in its Docker Compose setup. The free hosted plan costs nothing and allows 3 checks per month, while self-hosting permits unlimited local checks. Pro costs $9.99 a month and Premium costs $19.99 a month; Enterprise pricing is custom.

Pangram detects AI-generated text and images and offers plagiarism detection. Its text analysis covers material associated with ChatGPT, Gemini, Grok, Llama, and Claude, and it can highlight passages edited by AI rather than fully generated by AI. Users can submit PDF, DOCX, and RTF files, with uploads of up to 100 files at a time. Pangram says its detection works across more than 20 languages. A Chrome and Firefox extension scans feeds on sites including X, LinkedIn, Substack, Medium, Reddit, and Google Docs; listed integrations also include Canvas, Blackboard, Brightspace, Google Classroom, Moodle, Schoology, and Ashby. Pangram says submitted content is not used to train generalized AI models. Text remains stored while an account is active but can be deleted from dashboard history. The service has a free plan and a 7-day trial. Individual costs $20 per month billed annually, and Professional costs $65 per month billed annually. The site displays SOC 2 Type 2 verification by AssuranceLab.