JSON Formatter
Paste JSON to format (pretty-print), minify, and validate. Shows helpful syntax error hints. Everything runs locally in your browser.
Standard JSON only (no comments, no trailing commas, keys must be in double quotes). Press Ctrl/Cmd + Enter to format.
Privacy: runs locally in your browser. No JSON is stored or transmitted.
How it works
This tool uses JSON.parse to validate syntax and JSON.stringify to format or minify data.
How it works:
- Validate: checks if JSON is syntactically correct
- Pretty print: adds indentation for readability
- Minify: removes whitespace to reduce size
How to interpret results:
- Valid JSON → safe to use in APIs or configs
- Pretty JSON → easier debugging and editing
- Minified JSON → optimized for performance and transfer size
Examples
- API debugging: Format messy API responses to readable structure.
- Production optimization: Minify JSON before sending to reduce bandwidth.
- Validation: Check if JSON is valid before using in code.
Example:
- Input:
{"name":"app","users":[1,2]} - Pretty → structured output with indentation
- Minify → compact version without spaces
When to use this tool
This tool is designed for quick, practical tasks such as everyday calculations, data formatting, or simple conversions. It is best used when you need fast results without installing software or using complex tools.
When to use
- Quick checks or one-time calculations
- Validating or converting data before using it elsewhere
- Simple tasks that do not require advanced software
When not to use
- Critical financial, legal, or medical decisions
- Large-scale or automated processing
- Situations requiring guaranteed precision beyond basic validation
Always review results before using them in important contexts.
About this tool
This tool helps you format and validate JSON data for readability and debugging. It runs entirely in your browser without sending data to a server.
You can use this tool when working with APIs or cleaning up structured data. The results should be interpreted as a properly formatted JSON structure or validation feedback.
FAQ
- What does this JSON formatter do?
It formats JSON for readability, validates syntax, and can minify JSON to reduce size.
- Is my JSON uploaded?
No. All processing happens locally in your browser.
- Why is my JSON invalid?
Common issues include trailing commas, comments, missing quotes, or invalid values like NaN.
- When should I use minify?
Minified JSON is useful for APIs and production environments to reduce file size.
- When should I use pretty print?
Pretty format is ideal for debugging and reading JSON during development.
- Does it reorder keys?
Only if you choose sorting. Otherwise original order is preserved.
- What is JSON used for?
JSON is widely used for APIs, configuration files, and data exchange between systems.
- Can I format large JSON?
Very large JSON may impact browser performance. This tool includes size limits for stability.