JSON Formatter

About JSON Formatter

Parses and reformats JSON data with configurable indentation, then validates the structure and reports any syntax errors with the exact position of the problem. Paste minified or malformed JSON and get a properly indented, readable version in one step. The formatter uses JSON.parse under the hood, which means it enforces strict JSON: keys must be quoted strings, trailing commas are not allowed, and comments are not valid JSON. If parsing fails, the error output shows the character offset of the unexpected token — combined with a rough line number, this gets you to the problem quickly without manually scanning a wall of minified text. The minify toggle does the opposite: strips all whitespace to produce the most compact valid representation, reducing payload size for API requests or storage. Indentation options (2 spaces, 4 spaces, tabs) let you match whatever convention your codebase enforces. A common use case is inspecting API responses pasted from curl output or browser DevTools — the network tab shows minified JSON that is impossible to read at a glance. Another use: comparing two JSON objects side by side in the diff checker becomes much easier after formatting both through this tool first.

How to Use JSON Formatter Online

1. Paste your data into the input field above
2. The result appears instantly in the output area
3. Click "Copy" to copy the result to your clipboard

Pretty-print and validate JSON data. Runs 100% client-side — no data is sent to any server.

Frequently Asked Questions