JSON Formatter & Validator
Paste your unformatted JSON payload below. Formatting is applied securely in your browser.
How the JSON Formatter Works
This tool utilizes standard JavaScript JSON.parse() and JSON.stringify() running directly in your browser. When you paste data, the tool attempts to parse it into an Abstract Syntax Tree (AST). If the syntax is valid, it restrings it using either standard indentation (2 spaces) or no spaces (minified).
Why use a client-side formatter?
- Data Privacy: Production API keys, PII, and proprietary schemas never leave your device.
- Speed: Zero network latency. Processing happens at the speed of your local CPU.
- Offline Support: Once loaded, you can disconnect your internet and continue working.
Common JSON Formatting Errors
| Error | Cause |
|---|---|
| Unexpected token ' in JSON | JSON strictly requires double quotes (") for strings and keys. Single quotes (') are invalid. |
| Unexpected token } | Often caused by a trailing comma before the closing brace (e.g., "key": "value", }). |