Paste minified or messy JSON in the box. Click Format to get indented, readable output, or Minify to compress to one line. Invalid JSON shows an error with details. All processing runs in your browser — your data never leaves your device.
About the JSON Formatter
JSON is the standard data format for APIs, configs, and many apps. Often it arrives as one long minified line, which is hard to read or debug. This tool beautifies it with indentation and line breaks, validates it (and shows errors if invalid), and can minify it again for production. Everything runs in your browser — no upload, no server.How to Use JSON Formatter
- Paste your JSON into the input box (e.g. from an API response, log, or file).
- Click Format to get pretty-printed output with indentation, or Minify to compress to a single line.
- If the JSON is invalid, an error message appears with details. Fix the syntax and try again.
- Use Copy to copy the result. For CSV conversion, use JSON to CSV or CSV to JSON.
Key Features
- Pretty-print formatting — Transforms minified JSON into readable, indented output with standard 2-space indentation.
- Built-in validation — Automatically detects syntax errors and displays the parser's error message with position details.
- Minification mode — Compress formatted JSON to a single line for reduced payload size in production.
- One-click copy — Copy the formatted or minified result to your clipboard instantly.
- Strict JSON parsing — Enforces correct JSON syntax: double-quoted strings, no trailing commas, and valid escape sequences.
- 100% client-side — All formatting, validation, and minification happen in your browser with no server upload.
When to Use This Tool
- Reading or debugging API responses or configuration files that arrive as minified JSON.
- Validating JSON syntax before sending it to an API or storing it in a database.
- Minifying JSON payloads to reduce size for network transmission or storage.
- Quick formatting without opening an IDE, running a script, or installing a plugin.
Technical Details
Formatting uses JavaScript's built-in JSON.parse() and JSON.stringify() with standard 2-space indentation. The parser follows strict JSON rules: keys must be double-quoted strings, no trailing commas are allowed, and all escape sequences must be valid. When validation fails, the native parser error message is displayed, including the character position where the error was detected. For converting between JSON and other formats, see our YAML Converter, JSON/XML Converter, and JSON to CSV tools. For sorting keys alphabetically, use our JSON Key Sorter.
Conclusion
The JSON Formatter is an indispensable developer tool that combines formatting, validation, and minification in a single interface. With browser-based processing ensuring complete data privacy, it's the fastest way to make JSON readable, catch syntax errors, and prepare payloads for production.