JSON Formatter & Validator

Free Online JSON Formatter and Validator

JSON (JavaScript Object Notation) is the most widely used data interchange format on the web. Whether you're debugging an API response, cleaning up configuration files, or validating data structures, a good JSON formatter is an essential tool in every developer's toolkit.

What This Tool Does

Format: Takes minified or poorly formatted JSON and pretty-prints it with proper indentation (2 or 4 spaces). This makes nested structures readable and easy to scan.

Validate: Checks whether your JSON is syntactically valid. If there's an error, it tells you exactly where — the line and character position of the problem.

Minify: Removes all unnecessary whitespace, reducing file size. Useful for production configuration files and API payloads where every byte counts.

Common JSON Errors and How to Fix Them

• Trailing commas: JSON does not allow trailing commas after the last item in an array or object. Remove the comma before ] or }.
• Single quotes: JSON requires double quotes for strings. Replace 'key' with "key".
• Unquoted keys: All object keys must be double-quoted strings. {name: "value"} is invalid — use {"name": "value"}.
• Comments: JSON does not support comments. Remove any // or /* */ comments from your data.
• Special characters: Certain characters must be escaped in strings: \", \\, \n, \t.

JSON vs Other Data Formats

JSON vs XML: JSON is lighter, easier to read, and faster to parse. XML supports attributes and mixed content but is more verbose. Most modern APIs use JSON.

JSON vs YAML: YAML is more human-readable and supports comments, making it popular for configuration files. JSON is stricter and more widely supported in programming languages.

JSON vs CSV: CSV is better for tabular data and spreadsheet compatibility. JSON handles nested and hierarchical data that CSV cannot represent.

Best Practices for Working with JSON

Use consistent indentation (2 spaces is the most common convention). Keep nesting depth manageable — deeply nested JSON is hard to work with. Use meaningful key names. Validate JSON before sending it to APIs or storing it in databases.