Most file converters upload your documents to a server. MarkDone does everything locally in the browser — your files never leave your device. Tools available: Markdown → PDF (with LaTeX/KaTeX + syntax highlighting) Word (DOCX) → PDF README → PDF Mermaid diagrams → PDF JSON ↔ TOON (compact LLM-friendly format) JSON ↔ YAML No account. No upload. No BS.