JSON Formatter, Validator & Minifier

Paste any JSON to instantly format it with syntax highlighting, catch errors with precise line numbers, or compress it to its minimum size. Everything runs in your browser — nothing is ever sent to a server.

100% private: your JSON is processed entirely in your browser via JSON.parse() and JSON.stringify(). No data is sent to any server — safe for API responses, config files, and sensitive payloads.
Input
Paste JSON to begin
Output 

            

              
            

          


        


        
        

          
          
        


        
        

          
Frequently Asked Questions

          


            

              
What is JSON formatting (pretty-printing)?

              
JSON formatting, also called pretty-printing, adds consistent indentation and line breaks to a compact or minified JSON string. This makes the structure visually clear, with each key–value pair on its own line and nested objects indented. This tool uses 2-space indentation by default — the most common convention — but you can switch to 4 spaces or tabs.

            


            

              
What does JSON validation check?

              
JSON validation confirms that a string conforms to the JSON specification (RFC 8259). Common errors include trailing commas, single-quoted strings, unquoted keys, comments, and unclosed brackets or braces. This tool uses the browser's native JSON.parse() to validate, which follows the spec strictly and reports the exact position of the first error found.

            


            

              
What is JSON minification?

              
JSON minification removes all unnecessary whitespace, line breaks, and indentation from a JSON string, producing the smallest valid representation. This reduces file size for network transmission and storage. Minified JSON is semantically identical to its formatted version — only whitespace outside of string values is removed.

            


            

              
Is my JSON data sent to a server?

              
No. All processing happens entirely in your browser using JavaScript's built-in JSON.parse() and JSON.stringify(). Your data is never transmitted anywhere — which is especially important when working with API responses, configuration files, or data that may contain sensitive information.

            


            

              
What is the difference between JSON and JSON5?

              
Standard JSON (RFC 8259) is strict: keys must be double-quoted strings, trailing commas are forbidden, and comments are not allowed. JSON5 is a superset that allows unquoted keys, trailing commas, comments, single-quoted strings, and other conveniences inspired by JavaScript object literals. This tool validates and processes standard JSON only — for JSON5 you would need a dedicated parser library.