Unlike JPEG images, PDF documents, or MP4 videos, the .fzz format is . Your default operating system (Windows, macOS, Linux, Android, or iOS) does not recognize it. Double-clicking an .fzz file will likely result in an error: "Windows cannot open this file" or "No application found to open FZZ document."
An .fzz file is a "Shareable Project File" used by the Fritzing application. Unlike standard image files, an FZZ file is a compressed archive containing: fzz viewer