JSON Formatter
Paste JSON or open a local file to format, validate, or minify it. The formatter reports syntax errors with line and column numbers, preserves numeric text in the formatted output, and offers a bounded tree preview for exploring objects and arrays.
Your JSON
Paste JSON or open a local .json file. Processing stays in this tab.
How to format JSON
Paste JSON into the editor or choose a local .json file, then select Format JSON. The result uses two or four spaces per nesting level. Copy it or download a .json file.
The formatter changes whitespace outside strings. It does not reserialize numbers, so an integer such as 9007199254740993 keeps its exact digits in the formatted text.
Validate JSON and find errors
Select Validate JSON to check whether the input follows JSON syntax. If parsing fails, the tool reports the parser message and a line and column when the browser provides a position.
Common problems include trailing commas, unquoted property names, single-quoted strings, and comments. Standard JSON requires double-quoted strings and property names.
Minify JSON
Select Minify JSON to remove whitespace outside strings. Whitespace inside a quoted string stays unchanged. The output can be copied or downloaded.
Minification reduces presentation whitespace; it does not compress the file or change JSON values.
Explore the JSON tree
After successful validation, expand objects and arrays in the tree viewer to inspect their entries. The preview is bounded so a large document does not create an enormous page.
JavaScript parses numbers as floating-point values for this preview. If exact large integer values matter, use the formatted text, which retains their original digits.
Examples
Format an object
1Input
{"name":"Olivez","active":true}
Show result
Result
{ "name": "Olivez", "active": true }
Minify an array
2Input
[ 1, 2, 3 ]
Show result
Result
[1,2,3]
Frequently Asked Questions
Is this JSON formatter free?
Yes. You can format, validate, minify, copy, and download JSON without an account.
Does the formatter change large numbers?
The formatted and minified text preserves numeric digits from the input. The optional tree preview uses JavaScript numbers and can round values outside the safe integer range.
Can I format a JSON file?
Yes. Open a local file smaller than 1 MB. It is read and processed in your browser.
Why is my JSON invalid?
JSON requires double-quoted keys and strings and does not allow trailing commas or comments. The validation result shows a parser message and location when available.
Is my JSON uploaded?
No. Parsing and formatting happen in your current browser tab.