Check-Plagiarism vs Plagius

Check-Plagiarism is a plagiarism-checking service for students, teachers, researchers, content creators, and digital publishers. It accepts pasted or typed text and DOC, DOCX, TXT, or PDF uploads, with a listed maximum of 7,000 words per document. The checker reports duplicated passages, sentence-level matches, similarity percentages, and matching sources. Its AI is described as detecting paraphrased or lightly edited text as well as exact matches. The service says it checks billions of web pages and provides access to academic databases and publications, with support claimed for more than 20 languages. Reports can be downloaded or shared, including as PDF. Free online use is available with limited searches; registered accounts can increase the limit. Plans include Monthly at $14.99 a month and Annual at $8.33 a month, billed $99.99 every 12 months. API access and LMS integrations are listed.

Plagius Desktop analyzes academic papers and other documents for possible plagiarism, checking the internet or local files. It supports Word, PDF, OpenOffice, PPT, HTML, RTF, and plain-text formats. Reports can identify suspicious phrases and sources, display URLs with similarity percentages, estimate suspected-plagiarism percentages, and show analysis-quality indicators; results can be opened in a browser or exported as HTML. Its V5 AI detector analyzes paragraphs in context and returns an AI-generation probability and confidence level. The site says it recognizes signals from more than 15 models, including Gemini 3.7, GPT 5.6, and Claude 5. Professional desktop plans add local and network-share searches, batch analysis, direct URL analysis, and file comparisons. The maker says desktop analysis is performed locally, but external searches may send text fragments, usually 7 to 13 words, to search engines. AI detection may send isolated paragraphs to Plagius servers, where excerpts are deleted within up to 48 hours. A free demo runs analysis but reveals only some results. Plagius One is browser-based and initially limited to invited users. Plagius Basic costs $6.90, paid once; its license lasts 30 days and is for one Windows computer. The maker cautions that automated results need manual review and cannot alone confirm plagiarism.