JSON Formatter
Format, minify, and validate JSON. Pretty-print with configurable indentation. 100% client-side.
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What is this tool?
JSON formatter validates, prettifies, and minifies JSON data. It formats ugly or minified JSON into a readable, indented structure with syntax highlighting. Also detects and reports syntax errors with line numbers. Essential for API development, data debugging, and configuration file editing.
When to use this tool
API response debugging
Paste minified API responses to get a readable, indented format. Essential for debugging REST API integrations and understanding nested data structures.
Configuration file editing
Work with JSON configuration files (package.json, tsconfig.json, etc.) with proper indentation and syntax validation to catch errors before deployment.
Data validation
Check if your JSON data is valid before using it in applications. Invalid JSON syntax is a common source of bugs in web development and data pipelines.
How to use
- 1
Paste JSON
Enter your JSON data in the input area.
- 2
Format or minify
The tool auto-formats. You can also minify to compact form.
- 3
Copy result
Click to copy formatted JSON to clipboard.
Frequently Asked Questions
What is valid JSON?
Valid JSON follows strict syntax rules: double-quoted keys and string values, no trailing commas, no comments, and only specific data types (object, array, string, number, boolean, null). Common errors include single quotes, trailing commas, and unquoted keys.
What is the maximum JSON size supported?
This tool processes JSON entirely in your browser. Practical limits depend on your browser memory—typically several megabytes. For very large files, consider command-line tools like jq.
Can I use this in production?
This tool is designed for development and testing. For production use established libraries with security audits.