JSON Formatter & Validator
Paste JSON to validate, format, or minify it. Your data stays in this browser.
Formatted Output
Formatted JSON will appear here. Add input, then choose Format or Minify.
Validation and formatting run in your browser. Your JSON is not uploaded or stored.
How to format and validate JSON
Paste a JSON value above and choose Format to add readable indentation or Minify to remove extra whitespace. Formatted output uses 2 spaces by default; choose 4 spaces or a tab to change indentation. Validation updates as you type, and you can copy the result when it is ready.
Example
This compact input becomes the indented output shown below:
Input
{"name":"Mira","active":true}Formatted
{
"name": "Mira",
"active": true
}Common JSON errors
JSON requires double quotes around property names and text values. Comments and trailing commas are not allowed. This validator also rejects duplicate property names within the same object; its duplicate-key message lists the names and currently reports an approximate location at line 1, column 1.
Limits and privacy
Input is limited to 1 MB. Validation, formatting, and minifying happen in your browser; the JSON is not uploaded or stored. JavaScript can lose precision for integers outside its safe range (−(253−1) through 253−1). If exact large-number digits matter, avoid parsing and reserializing that value here.
Need to compare two JSON values? Try the JSON Diff. To work with tabular data, use JSON to CSV or CSV to JSON.