ZFO File Opener

ZFO File Opener is a web-based tool for opening and converting ZFO files (Czech digital mailbox container files) directly in your browser without requiring any software installation. The service allows users to preview file contents, extract individual documents, verify digital signatures, and download documents as PDF or ZIP archives. The tool operates entirely client-side, ensuring files never leave your device, and works seamlessly across desktop and mobile browsers. It's designed for individuals and businesses in the Czech Republic who need to access, read, and convert digitally signed messages from the Czech data box (datová schránka) system.