JSON Formatter & Validator
Paste your JSON to format, validate, beautify, or minify it instantly. Syntax highlighting with line numbers, interactive tree view, and 2-space, 4-space, or tab indentation. Pretty print JSON online and download formatted output as a .json file.
JSON Formatting Tips
Validate before shipping
Always validate JSON before sending to APIs or saving to config files. A single trailing comma can break everything.
Choose your indentation
2 spaces for JS/TS projects, 4 spaces for Python/Java, tabs for personal preference. Stay consistent within a project.
Minify for production
Remove whitespace to reduce payload size. A 50KB formatted JSON file can shrink to 20KB minified.
Use double quotes
JSON requires double quotes for strings and keys. Single quotes, unquoted keys, and trailing commas are not valid JSON.
Check nested structures
Errors often hide in deeply nested objects or arrays. Use tree view to visually inspect the structure level by level.
Handle special characters
Escape backslashes, quotes, and control characters in strings. Use \n for newlines and \t for tabs inside JSON values.
Frequently Asked Questions
What is JSON formatting?
JSON formatting (also called “pretty-printing” or “beautifying”) adds consistent indentation and line breaks to raw JSON data, making it easier to read and debug. This tool parses your JSON and re-serializes it with your chosen indentation level (2 spaces, 4 spaces, or tabs).
What does minifying JSON do?
Minifying removes all unnecessary whitespace from JSON, producing the smallest possible output. This is useful for reducing payload sizes when sending JSON over a network or storing it in databases.
How do I fix “Unexpected token” errors?
This usually means your JSON has a syntax error such as a trailing comma, missing quote, or unescaped special character. Check the line and column number shown in the error message to locate the issue. Common fixes include removing trailing commas after the last item in an array or object, and ensuring all strings are double-quoted.
What indentation should I use for JSON?
2 spaces is the most common convention in JavaScript and TypeScript projects. 4 spaces is popular in Python and Java ecosystems. Tabs are preferred by developers who want customizable visual width. For minified production JSON, no indentation is used.
What is the tree view?
The tree view displays your parsed JSON as a collapsible, interactive tree structure. Each object and array can be expanded or collapsed individually, making it easy to navigate deeply nested data. Data types are color-coded so you can identify strings, numbers, booleans, nulls, arrays, and objects at a glance.
How do I pretty print JSON?
Paste your raw or minified JSON into the input area and click “Format / Beautify”. Choose your preferred indentation (2 spaces, 4 spaces, or tabs) from the dropdown. The output panel will show your JSON with syntax highlighting and line numbers for easy reading.
How do I format JSON in the command line?
You can use python -m json.tool file.json or jq . file.json on Linux/macOS, or pipe JSON via echo {"key":"value"} | jq .. However, this online tool is faster for one-off formatting and provides syntax highlighting, tree view, and validation that CLI tools don't offer.
Is my data safe?
Yes. All processing happens entirely in your browser using JavaScript's built-in JSON.parse and JSON.stringify. No data is sent to any server.