What JSON is
A compact format for structured data
JSON, or JavaScript Object Notation, represents data with objects, arrays, strings, numbers, booleans, and null. APIs, configuration files, web applications, and data exports use it because it is both machine-readable and reasonably easy for people to inspect.
Why formatting matters
Make structure visible without changing the data
Pretty formatting adds indentation and line breaks so nested values are easier to review and debug. Minifying removes that extra whitespace when you need a smaller payload. Both operations preserve the parsed JSON data.
Common validation errors
Small syntax mistakes that stop JSON from parsing
- Trailing commas after the last property or array item
- Single quotes instead of required double quotes
- Property names without double quotes
- Missing commas between values or properties
- Unmatched braces, brackets, or quotation marks
- Comments, which standard JSON does not support
Examples
From compact input to readable output
| Input | Result |
|---|---|
{"active":true,"count":3} | Valid object; can be pretty formatted |
{"items":[1,2,3]} | Valid object containing an array |
{"name":"Ada",} | Invalid because of the trailing comma |
Data Toolkit
Work with common data formats in one private workspace
FAQ
Questions about formatting and validating JSON
Does UtilityDock upload or store my JSON?
No. Your files never leave your computer. Parsing, validation, formatting, minifying, and download creation all happen locally inside your browser.
What makes JSON invalid?
Common causes include trailing commas, single quotes, missing commas, unquoted property names, unmatched brackets, and comments.
What is pretty-printed JSON?
Pretty-printed JSON uses indentation and line breaks to make nested objects and arrays easier for people to read.
Does minifying JSON change its data?
No. Minifying removes insignificant whitespace while preserving the parsed values, keys, arrays, and nesting.
Does this tool validate a JSON Schema?
No. Version 1 checks JSON syntax only. It does not test values against a JSON Schema or run JSONPath queries.