Features
- Format and pretty-print JSON with indentation
- Minify JSON to single-line compact form
- Live error highlighting with line numbers
- Syntax highlighting
- Tree view for nested structures
- Copy formatted or minified output
- No signup, no uploads to server
How it works
- Open freejsonformatter.app
- Paste JSON into the input
- See formatted output with validation instantly
- Copy formatted or minified version
Common use cases
- Debugging API responses
- Preparing JSON for configuration files
- Validating JSON schema output
- Minifying for production or embedding
- Understanding nested JSON structures
How it compares
JSONLint is a classic choice but ad-supported. JSON Viewer Pro and similar extensions add features but require installation. Freejsonformatter is ad-free, browser-native, and works offline.
Privacy
JSON stays in your browser. Nothing is sent to any server — important when working with sensitive API data.