How to Pretty-Print JSON (Browser, CLI, and Code)

Why Pretty-Print at All?

Minified JSON is great for the wire; it is punishing for humans. Pretty-printing adds indentation and newlines so you can scan structure, spot missing keys, and diff changes.

Use minified in production, pretty in editors, logs a developer will actually read, and anywhere Git will diff the file.

The Two-Space Convention

Most tools and style guides use two-space indentation. It keeps files narrow enough to diff and wide enough to read.

Four spaces is common in some Python projects; tabs are rare and generally discouraged for JSON.

Step-by-Step: In the Browser

The console is faster than any online tool for one-off cases.

const data = JSON.parse(text);
console.log(JSON.stringify(data, null, 2));

const sorted = JSON.stringify(data, Object.keys(data).sort(), 2);

Step-by-Step: In the Terminal

jq is the swiss-army knife for JSON on the command line.

# Pretty-print a file
jq . data.json

# Pretty-print from a pipe
curl -s https://api.example.com/orders | jq .

# Two-space indent (default is two)
jq --indent 2 . data.json > pretty.json

python -m json.tool data.json > pretty.json

Step-by-Step: In Code

Every mainstream language has a one-liner.

fs.writeFileSync("pretty.json", JSON.stringify(data, null, 2));

import json
with open("pretty.json", "w", encoding="utf-8") as f:
    json.dump(data, f, indent=2, ensure_ascii=False, sort_keys=True)

b, err := json.MarshalIndent(v, "", "  ")

Editors and Formatters

You rarely need a website to format JSON.

• VS Code: Shift+Alt+F (Format Document).
• IntelliJ/WebStorm: Ctrl+Alt+L (Reformat Code).
• Prettier: --parser json on the command line.
• Vim: :%!jq . if jq is installed.

Real-World Examples

The formatting choice depends on the audience.

Common Mistakes

Small formatting issues cause big review pain.

• Mixing indent widths within one file.
• Losing the trailing newline (some tools require it).
• Turning off sort_keys and getting noisy diffs.
• Pretty-printing 100 MB responses in production logs.
• Trusting an online formatter to strip comments—JSON does not have comments.

Best Practices

A short list that keeps files pleasant.

• Use 2 spaces by default.
• Sort keys for committed files.
• End files with a newline.
• Prefer editor formatters over web tools for privacy.
• Minify at the network boundary, pretty at rest.

Why Use Convert CSV Online?

When your JSON originates from a CSV, Convert CSV Online is free, browser-based, and needs no account for everyday conversions. It produces pretty JSON directly, ready to commit or hand to stakeholders. Client-side workflows run on Windows, macOS, and Linux browsers.

Conclusion

Pretty-printing JSON is a one-liner in every language and a one-shortcut task in every editor. Use it for anything a human will read; keep the wire minified.