Validate JSON syntax, format readable output or remove unnecessary whitespace.
n Inputs are processed locally by this tool. Other site plugins, hosting logs, ads and embeds have their own data handling. Text limit: 1 MiB UTF-8.
How to use JSON Formatter, Validator & Minifier
- Paste valid JSON.
- Choose format or minify.
- Run the tool; correct any syntax error before copying the output.
Example
{"items":[1,2]} becomes an indented object in format mode. Trailing commas are invalid JSON.
Method and formula
JSON.parse validates the input; JSON.stringify reserializes it with two-space indentation or no extra whitespace. Browser syntax errors are displayed clearly. Formatting does not validate a schema or evaluate code.
Limits and supported input
JavaScript Number uses IEEE-754 double precision: integers outside ±9,007,199,254,740,991 can lose precision, and decimal representations may change. Duplicate object keys keep the last value; property order can normalize. Do not use this for byte-exact or high-precision financial data.
Privacy
This tool processes the input in your current browser tab. It does not upload your input or call a paid or remote API. Copying places text on your system clipboard; downloading saves a file on your device. Site hosting logs, analytics, ads, third-party embeds and other installed plugins are separate and can have their own data handling. JavaScript is required for the tool, while this explanation remains available without it.
Frequently asked questions
Does this support comments?
No. Standard JSON does not support comments.
Will large numeric IDs stay exact?
Not always. Store identifiers as strings or use a precision-preserving parser elsewhere.