Copyleaks AI Detector vs Plagium

Copyleaks AI Detector identifies AI-written text, including writing that mixes AI and human passages. It supports more than 30 languages and names GPT-5, GPT-4, ChatGPT, Claude, Gemini, DeepSeek, Llama, Bloom, Rytr, and Jasper among the sources it detects. AI Logic explains flagged results, displays AI phrase frequency, and can identify text appearing in published content elsewhere. The web detector scans up to 25,000 characters without login; the website platform requires at least 255 characters and accepts up to 2,000 pages. A Chrome and Edge extension accepts 350 to 25,000 characters, and a Google Docs add-on and education LMS integrations connect it to other workflows. Personal costs $13.99 a year with annual billing or $16.99 a month; Pro costs $74.99 a year with annual billing or $99.99 a month. A free plan and free trial are listed. Copyleaks says data is encrypted at rest with AES-256, reports SOC 2 and SOC 3 certifications, and supports GDPR compliance.

Plagium analyzes text for similarity with other material and offers a separate tool for identifying patterns compatible with AI-generated writing. Its plagiarism service compares submitted text with an online database and reports similarities with links to original sources. The AI Detector uses statistical and probabilistic analysis of writing patterns. Deep Search accepts Microsoft Word, PDF, and native text files; Google Drive integration and a Google Docs add-on support document analysis. Institutional users can access an API, while business solutions can integrate with corporate CRM, ERP, and document-management systems. Plagium presents solutions for educational institutions, publishers, editors, companies, researchers, and compliance teams. The free account costs nothing and allows five daily searches with a 4,000-character limit, but excludes Deep Search and API access. Plagium says submitted content remains owned by the user and is processed for analysis, report generation, and service improvement. Reports are automated estimates rather than definitive proof, and private, unpublished, or non-indexed material may not be detected.