JSON Formatter: How to Format, Validate, and Debug JSON

Why JSON Formatting Matters

Production JSON is minified — all whitespace removed to reduce file size. A 200-field API response looks like an unreadable wall of text. A JSON formatter transforms it into readable, navigable structure with proper indentation.

Valid JSON: The Six Rules

Keys must be double-quoted: {"name": "value"} not {name: "value"}

Strings use double quotes only: {"city": "Delhi"} not {'city': 'Delhi'}

No trailing commas: {"a": 1, "b": 2} not {"a": 1, "b": 2,}

No comments: // and /* */ are not valid in JSON

Use null not undefined

Boolean and null lowercase: true, false, null — not True, False, Null

Common JSON Errors

Unexpected token: Usually a missing comma or extra comma between properties.

Expected property name: Key without double quotes — wrap it.

Unexpected end of JSON: Unclosed bracket or brace — count opening vs closing.

Using Lazyblink JSON Formatter

Paste your JSON in the input area

Errors highlight immediately with the line number

Valid JSON appears formatted with 2-space indentation

Use Minify to compress back to one line

Copy the formatted output

JSON in Different Contexts

API debugging: Copy from browser DevTools Network tab, paste into formatter to explore structure.

Config files: package.json, tsconfig.json — format before committing.

MongoDB queries: Format complex aggregation pipelines before running.