JSON Formatting Best Practices for 2026

While machines can read minified JSON without any issues, humans need properly formatted data to debug, configure, and maintain software. Implementing JSON formatting best practices across your engineering team ensures consistency and reduces friction.

1. Standardize Indentation (2 spaces vs 4 spaces)

The eternal debate! For web APIs and large payloads, 2-space indentation is the industry standard. It keeps the payload size relatively small while offering clear visual hierarchy.

For configuration files (like package.json or system configs), 4-space indentation is often preferred because readability is more important than file size.

2. Maintain Consistent Key Casing

JSON doesn't enforce a specific casing style, but your team should. The most common conventions are:

• camelCase: Most common in JavaScript/TypeScript environments (e.g., "userId").
• snake_case: Frequently used in Python and Ruby backends (e.g., "user_id").

Whichever you choose, stick to it. Mixing firstName and last_name in the same object is a recipe for parser errors.

3. Order Keys Logically

Alphabetizing keys isn't strictly necessary, but ordering them logically helps. Put identifying fields (id, type, name) at the top of the object, followed by attributes, and end with nested objects or arrays.

4. Validate Before Formatting

Formatting broken JSON can behave unpredictably. Always validate your syntax first. Use a reliable JSON Validator to catch missing quotes or trailing commas.

5. Automate formatting in CI/CD

Don't rely on humans to remember formatting rules. Hook up a linter (like Prettier or ESLint) in your pre-commit hooks to automatically format JSON files before they are merged into the main branch.