Is there a standard on JSON naming?

No, there’s no single, universal “official” standard dictating how JSON keys must be named. The core JSON specification (ECMA-404) defines how data should be structured (objects, arrays, strings, etc.) but doesn’t prescribe naming conventions for your keys or fields.

However, several community-driven best practices and style guidelines can help you keep your data consistent, clear, and user-friendly. Below, we’ll explore some of the most common naming styles and offer tips on when to use each.

1. Common JSON Naming Styles

1. camelCase

   {
     "userName": "Alice",
     "userAge": 25
   }

   • Used By: Many JavaScript developers follow this pattern, aligning with typical JS variable naming.

2. snake_case

   {
     "user_name": "Alice",
     "user_age": 25
   }

   • Used By: Some Python and Ruby ecosystems prefer snake_case, since it’s typical in those languages.

3. PascalCase

   {
     "UserName": "Alice",
     "UserAge": 25
   }

   • Used By: Certain .NET or C# codebases, or for generating classes automatically from JSON (e.g., in strongly typed languages).

4. kebab-case (less common)

   {
     "user-name": "Alice",
     "user-age": 25
   }

   • Used By: Some config files and certain front-end frameworks. But dashes (-) can be awkward if you’re using dot notation in JavaScript.

2. What About “Official” Guidelines?

The short answer: There’s no single “official” JSON naming standard like you might find for some programming languages or frameworks. Instead, different ecosystems adopt consistent naming across their data.

Some API-specific guidelines:

• REST APIs often use snake_case or camelCase, depending on the background language or the team’s preference.
• JSON:API (a specification for RESTful APIs) suggests camelCase for consistency, but it doesn’t enforce it strictly.
• OpenAPI/Swagger doesn’t mandate a case format either; you choose what fits your domain best.

3. Best Practices for Choosing a Naming Convention

1. Consistency Is Key
   Whatever style you pick—be it snake_case, camelCase, or PascalCase—remain consistent across your entire API or project. Switching styles midstream creates confusion for developers consuming your data.

2. Match Your Main Codebase
   If you’re a Python-heavy organization, snake_case might feel natural. In a JavaScript-focused team, camelCase aligns well with typical variable naming.

3. Favor Readability

   • Minimal abbreviations.
   • Use descriptive keys (e.g., "account_balance" instead of "accBal").

4. Document Your Decision
   Clearly state your naming convention in your project’s style guide or API docs. This helps new team members or external users know what to expect.

4. Examples of a Clear, Consistent JSON

Here’s a camelCase example that’s both descriptive and uniform:

{
  "userName": "Alice",
  "userAge": 25,
  "accountBalance": 1000.0,
  "preferredLanguages": ["JavaScript", "Python"]
}

• Consistency: All keys are in camelCase.
• Clarity: Names are descriptive and easy to understand.

Level Up Your System Design & Coding Interview Skills

Choosing the right naming convention is part of building maintainable, scalable systems. If you’re looking to sharpen your design and coding skills, here are some recommended courses from DesignGurus.io:

1. Grokking System Design Fundamentals

   • Ideal for beginners who want to learn the basics of system design, including data modeling and consistent naming practices.

2. Grokking the System Design Interview

   • A deeper dive into real-world architecture scenarios, trade-offs, and best practices—key for high-level design interviews.

3. Grokking the Coding Interview: Patterns for Coding Questions

   • Strengthen your problem-solving skills with pattern-based approaches to coding challenges often asked in technical interviews.

Final Thoughts

There’s no singular, globally mandated JSON naming convention, but adopting a consistent style is essential for clarity and ease of use—particularly in large codebases or public APIs. Whether you choose camelCase, snake_case, or another approach, the important part is documenting it and applying it uniformly throughout your project.

This consistency is what transforms an ad-hoc JSON file into a well-structured, developer-friendly interface.