JSON Formatter & Validator
Format, validate and beautify JSON data. Minify or pretty-print with customizable indentation.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data interchange format used by virtually every web application and API. Created by Douglas Crockford in the early 2000s, JSON has become the standard format for transmitting structured data between servers and clients, replacing XML in most modern applications.
A JSON formatter (also called a JSON beautifier or JSON pretty-printer) takes compact or messy JSON data and reformats it with proper indentation and line breaks, making it human-readable. This is essential for debugging API responses, editing configuration files, and understanding complex data structures.
Why Format JSON?
- Debugging API responses — Raw API responses are often minified. Formatting reveals the data structure.
- Editing config files — Package.json, tsconfig.json, and other config files are easier to edit when formatted.
- Validating data — Quickly find syntax errors like missing commas, unclosed brackets, or invalid types.
- Sharing with teammates — Formatted JSON is easier for others to read and review.
Common JSON Errors
- Trailing commas — JSON does not allow a comma after the last item in an array or object.
- Single quotes — JSON requires double quotes for strings. Single quotes are invalid.
- Unquoted keys — All keys must be enclosed in double quotes.
- Comments — Standard JSON does not support comments (// or /* */).
- Missing brackets — Every { must have a matching } and every [ needs a ].
Frequently Asked Questions
Is my JSON data safe?
Yes. This JSON formatter runs entirely in your browser using JavaScript. Your data is never sent to any server — all parsing and formatting happens locally.
What's the difference between formatting and minifying?
Formatting (beautifying) adds indentation and line breaks to make JSON readable. Minifying removes all unnecessary whitespace to reduce file size — useful for production APIs and network transfer.
Can I use tabs instead of spaces?
Yes. Our formatter supports 2-space, 4-space, and tab indentation. Choose the format that matches your project's style guide.