JSON Formatter

What Is the JSON Formatter?

The JSON Formatter formats, validates, and minifies JSON (JavaScript Object Notation) in your browser. Paste compact, minified, or messy JSON and it returns clean, indented JSON that is easy to read, check, and share. If the JSON is invalid, it reports the problem so you can fix it before using the data in an app, API test, or configuration file.

JSON is a text format for structured data made of objects, arrays, strings, numbers, booleans, and null. This tool does not change the meaning of valid JSON. It only changes whitespace and layout, and it can also remove whitespace to produce a compact one-line version.

How to Use the JSON Formatter

1. Paste your JSON into the input box. You can also type it directly.
2. Choose an indent size if the option is shown, for example 2 spaces or 4 spaces.
3. Click Format to beautify the JSON, or Minify to compress it to one line.
4. Check the output. If there is a syntax error, read the error message, fix the input, and format again.
5. Click Copy to copy the formatted result, or click Validate if you only want to check whether the JSON is valid.

Worked Example

Suppose you paste this minified JSON:

{"name":"Asha","age":29,"city":"Pune","skills":["HTML","CSS"]}

With 2-space indentation, Format returns:

{
  "name": "Asha",
  "age": 29,
  "city": "Pune",
  "skills": [
    "HTML",
    "CSS"
  ]
}

The data is unchanged: name is still Asha, age is still 29, and skills still has 2 items. Minify reverses this and returns the original one-line version. If you paste {"name":"Asha",}, the tool reports an error because of the trailing comma after the last value.

Limitations

• Input must be valid JSON. JavaScript object literals with unquoted keys, single quotes, trailing commas, comments, or undefined are not valid JSON and will fail validation.
• Very large files may be slow on low-memory devices, and extremely large pastes can hit browser clipboard or input limits.
• Numbers follow JavaScript number precision. Very long integers may lose precision when parsed.
• The tool checks syntax only. It does not check whether field names or values are correct for your API or schema.
• Duplicate object keys are allowed by some parsers but later values may overwrite earlier ones when the JSON is used elsewhere.

Frequently Asked Questions

What is the difference between Format and Minify?

Format adds line breaks and indentation so JSON is easy to read. Minify removes unnecessary whitespace so JSON is as small as possible. Both keep the same data.

Why does my JSON show a syntax error?

Common causes are a missing comma, a missing closing brace or bracket, an unquoted key, a single-quoted string, or a trailing comma. Fix the reported position and try again.

Does formatting change my data?

No. Formatting only changes whitespace. Key order and values stay the same in the formatted output.

Can I format JSON with comments?

No. Standard JSON does not allow comments. Remove comments before formatting, or use JSONC / JSON5 handling in a code editor if your project uses those variants.