Format and Validate JSON
Clean up difficult-to-read JSON, reduce it for transport, or check it for syntax errors. Processing happens in a local Web Worker so your data stays in the browser.
JSON stays in your browser. Nothing is sent to a server.
Up to 5 million input characters. Processing runs in a local Web Worker.
What you can do with this tool
- Pretty-print JSON with readable indentation or minify it for compact output.
- Validate syntax and show an error line and column when possible.
- Paste, edit, copy, or download JSON locally with support for inputs up to 5 million characters.
How to use JSON Formatter & Validator
- Paste or type JSON into the input editor, or load the sample.
- Choose Format, Minify, or Validate.
- Copy the result or download the formatted JSON file.
When this tool is useful
- Make a compact API response easier to inspect during debugging.
- Validate a JSON configuration before passing it to another tool or service.
Limits and privacy
The formatter checks JSON syntax, not an application's schema or business rules. Inputs can be up to 5 million characters, but available memory and browser performance may limit very large documents. Formatting runs locally in a Web Worker.
Frequently asked questions
Does the formatter send JSON to a server?
No. Formatting, minifying, and validation run in a local Web Worker in your browser.
What happens when JSON is invalid?
The tool reports the parser message and provides a line and column hint when the browser can determine one.
How much JSON can I process?
The input limit is 5 million characters. Very large documents may still depend on available browser memory.