Copyscape vs PlagiarismSearch

Copyscape checks web pages and newly written human- or AI-generated content for plagiarism and duplicate text found online. Its free checker scans a URL and presents a word-by-word comparison of results, but shows no more than 10 search results and limits scans per website. Premium accepts pasted text as well as PDF and Word uploads for originality checks. Its Batch Search can process up to 10,000 pages in one operation, with each page billed like a regular search. The Premium API can automate plagiarism and AI checks and return results in JSON, XML, or HTML; a WordPress plugin supports checks in a WordPress workflow. Premium users can create a private index of their own content, accessible only through their Copyscape account. Copysentry monitors selected pages daily or weekly and emails alerts when it finds copies. Enterprise can be hosted on-premises or in a private cloud. Copyscape says it uses Google for search and then processes results with proprietary algorithms. It warns that AI detector results may misclassify human or AI text and should not be the sole basis for disciplinary action.

PlagiarismSearch checks submitted writing against selected web, archived, publication, academic, and enabled organizational sources. Its reports identify matching or similar passages, link those passages to detected sources, and provide a similarity report. An AI writing feature gives probability indicators for the full text and individual passages, highlighting passages for review. The service also lists paper analysis, readability, and spelling and grammar tools. Users can check up to 150 words for free, while registered users can check up to 300 words daily at no charge. The maker says its academic database contains over 500 million indexed texts. Integrations include a Moodle plugin, Google Docs add-on, customizable API, and Viber and Telegram bots. The maker presents it for students, educators, writers, bloggers, universities, and organizations. Paid options include a Light one-time package at $9.95, paid once and monthly packages from $27.95 a month. The maker says uploaded documents are not stored, though reports may remain in an account until deleted by the user.