How to use this tool
How to format JSON
Paste valid JSON into the editor and choose Format. Objects and arrays are printed with two-space indentation. Choose Compact for a single-line representation, then Copy to copy the current editor content.
Formatting example
Input: {"name":"Prism","active":true}. Format separates the keys onto indented lines. Compact reverses the whitespace change. Neither action sorts keys or converts strings into numbers.
Understand conversion limits
Formatting parses the input and serializes it again. Duplicate object keys cannot be preserved; large integers beyond JavaScript’s safe integer range can lose precision. Use strings for exact large identifiers. JSONL input is converted to a JSON array when formatted.
Input and output example
Choose Format for indentation, or Compact for single-line JSON.
Input
{"active":true,"items":[1,2]}
Output
{
"active": true,
"items": [
1,
2
]
}
No sign-up required. JSON content is processed locally.