How do I pretty print JSON in JavaScript?

Use JSON.stringify(value, null, 2) to serialize the value with two-space indentation.

Can I pretty print invalid JSON?

No. The JSON must parse successfully before you can pretty print it.

Why pretty print during debugging?

It makes nested objects and arrays much easier to read and compare.

Can I use MyJSONTool instead of writing code?

Yes. Use the JSON Formatter or JSON Beautifier pages for quick browser-based formatting.

How to Pretty Print JSON in JavaScript

The basic approach

const output = JSON.stringify(data, null, 2);

The third argument controls indentation. A value of 2 is a common choice because it is readable without becoming too wide.

Example

const data = { user: { id: 42, name: "Ada" } };
console.log(JSON.stringify(data, null, 2));

{
  "user": {
    "id": 42,
    "name": "Ada"
  }
}

Common pitfall

If the input is a JSON string instead of an object, parse it first with JSON.parse. If the string is invalid, fix the syntax before trying to pretty print it.

Open JSON Formatter Open JSON Beautifier

FAQ

What does the third argument to JSON.stringify do?

It controls indentation in the output.

Can I pretty print a JSON string directly?

Only after parsing it into a JavaScript value with JSON.parse.

Why use pretty printing in logs?

It makes nested responses much easier to inspect while debugging.

Can I do this without code?

Yes. Use MyJSONTool’s formatter pages if you just want the output quickly.