This task can be performed using DevKitHub
Privacy-first dev tools, offline and secure.
Best product for this task

DevKitHub
dev-tools
DevKitHub offers over 40 essential developer tools, including generators, converters, and debuggers, all designed to work offline for maximum privacy. From QR code generators to JSON converters and code debuggers, DevKitHub ensures your data never leaves your device. Compatible with Mac, Windows, and Linux, it features syntax highlighting and theme options, with regular updates to keep you equipped with the latest tools.

What to expect from an ideal product
- DevKitHub runs entirely on your computer so your JSON files stay private and never get sent to external websites or servers
- The built-in JSON converter works offline which means you can process sensitive data without internet connection or privacy concerns
- You get instant JSON conversion without waiting for uploads, downloads, or dealing with slow online tools that might log your data
- The tool handles large JSON files locally on your machine instead of hitting file size limits that most web-based converters have
- Your JSON data remains secure on your device while you convert between formats, parse structures, or validate syntax without third-party access