MarkItDown AI is a browser-based document to Markdown converter for AI workflows, documentation, notes, and knowledge bases. It converts PDF, DOCX, PPTX, XLSX, HTML, CSV, JSON, and XML files into clean Markdown, subject to file structure and published limits. Browser Basic processes supported files locally for free and does not upload the source file. The output is useful for ChatGPT, Claude, Cursor, RAG, notes, docs, and knowledge bases. Enhanced conversion is a separate paid option for eligible scanned or complex files, starts at $14.90, and requires sign-in and explicit upload consent. MarkItDown AI is an independent tool site and is not an official Microsoft property.