ZFO File Opener

ZFO File Opener is a web-based tool that allows users to open and view ZFO files (digital message containers from Czech data boxes) directly in their browser without installing specialized software. The service extracts and displays message metadata, sender/recipient information, subject, delivery timestamps, and attached documents. Users can download individual documents as readable PDFs or export the entire message as a ZIP archive while keeping the original sealed ZFO file for official archival purposes.

Key features include free preview of message metadata and signature information, per-document or bulk PDF conversion, works on both desktop and mobile devices, and processes files locally on the user's device without uploading to external servers. The tool is designed for Czech users who regularly receive official communications through the national data box system (datová schránka) and need an accessible way to view and extract document contents.