What does 'pretty print' JSON mean?

Pretty printing (also called formatting or beautifying) adds indentation and line breaks to compact JSON to make it human-readable. The data is identical — only the whitespace changes. A JSON formatter parses the compact JSON and re-serializes it with consistent indentation.

How do I pretty print JSON in JavaScript?

Use JSON.stringify(data, null, 2) where the third argument is the number of spaces to indent. For example: JSON.stringify({name:'Alice', age:28}, null, 2) produces a formatted 2-space-indented JSON string. Pass 4 for 4-space indentation, or '\t' for tab indentation.

How do I pretty print JSON from curl?

Pipe the curl output to Python's json.tool: curl -s https://api.example.com/data | python -m json.tool. If you have jq installed, use: curl -s https://api.example.com/data | jq '.'

Does pretty printing change the JSON data?

No. Pretty printing only changes whitespace — spaces, tabs, and line breaks. The keys, values, and structure are exactly the same. A minified and a formatted version of the same JSON parse to identical objects.

How to Pretty Print JSON – Browser, JavaScript, Python, curl

Machine-generated JSON is compact and hard to read. Pretty printing — also called formatting or beautifying — adds indentation and line breaks that reveal the structure. Here are the fastest methods for every environment.

In the browser — the fastest option for one-off inspection

If you have a JSON blob from an API response or a log file and need to read it right now, paste it into the JSON Formatter. It formats the JSON instantly with a collapsible tree view and 2-space indentation. No setup, no install — works entirely in your browser.

In JavaScript — JSON.stringify with the space parameter

JSON.stringify(value, replacer, space) — the third argument controls indentation:

const data = {
    name: "Alice",
    age: 28,
    roles: ["admin", "editor"],
    address: { city: "London", country: "UK" }
};

// 2-space indent (most common)
console.log(JSON.stringify(data, null, 2));

// 4-space indent
console.log(JSON.stringify(data, null, 4));

// Tab indent
console.log(JSON.stringify(data, null, '\t'));

Pass null as the second argument to include all keys. See the full guide on JSON.stringify indent options for more on the replacer parameter.

In Python — json.dumps with indent

import json

data = {"name": "Alice", "age": 28, "roles": ["admin", "editor"]}

# 2-space indent
print(json.dumps(data, indent=2))

# Sorted keys + 2-space indent
print(json.dumps(data, indent=2, sort_keys=True))

For more Python-specific options including file reformatting, see How to Format JSON in Python.

In curl — pipe to python -m json.tool or jq

The quickest way to pretty-print an API response directly in your terminal:

# Using Python's built-in json.tool (no extra install required)
curl -s https://api.example.com/users | python -m json.tool

# Using jq (if installed — more powerful, colorised output)
curl -s https://api.example.com/users | jq '.'

# Format and save to file
curl -s https://api.example.com/users | python -m json.tool > users-formatted.json

In Node.js

const https = require('https');

https.get('https://api.example.com/data', (res) => {
    let body = '';
    res.on('data', chunk => body += chunk);
    res.on('end', () => {
        const data = JSON.parse(body);
        // Pretty-print to console
        console.log(JSON.stringify(data, null, 2));
    });
});

In VS Code

Open a .json file and press Shift+Alt+F (Windows/Linux) or Shift+Option+F (Mac) to format the document using VS Code's built-in JSON formatter. This respects your editor's indentation settings.

When to pretty-print vs when to minify

Pretty print during development, debugging, and code review — it makes structures clear at a glance. Minify for production payloads where bandwidth matters. Use the JSON Minifier to strip all whitespace before shipping JSON over the network.