How to Format and Validate JSON Like a Pro

Table of Contents

• What is JSON?
• Why Formatting Matters
• Validating JSON
• Common Formatting Mistakes
• Conclusion

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy for humans to read and write, and easy for machines to parse and generate.

{
  "name": "HeoLab",
  "type": "developer-tools",
  "features": ["json-formatter", "jwt-decoder", "base64"],
  "active": true
}

Why Formatting Matters

Unformatted JSON is notoriously hard to read. Consider this minified API response:

{"user":{"id":1,"name":"Trong","roles":["admin","user"]}}

vs. the formatted equivalent — one glance and you understand the structure. When debugging production issues at 2am, that difference is everything.

Validating JSON

JSON must follow strict rules:

• Keys must be strings wrapped in double quotes
• Trailing commas are not allowed
• Comments are not supported
• Values must be: string, number, object, array, boolean, or null

Common Formatting Mistakes

Conclusion

Mastering JSON formatting and validation is a small investment with a huge return. Use the JSON Formatter on HeoLab to paste, format, and validate any JSON instantly.