Processed locally — your file never leaves your device
JSON Formatter
Pretty-print JSON with configurable indentation — paste text or open a file, entirely in your browser.
How it works
- Paste JSON, or open a .json file.
- Choose 2 spaces, 4 spaces, or tabs for indentation.
- Click Format — invalid JSON shows a clear error instead of a result.
- Copy the result or download it, all without anything leaving your browser.
Frequently asked questions
- Is my JSON uploaded anywhere?
- No. Formatting happens locally in your browser, using only JavaScript's own JSON parser.
- What happens if my JSON is invalid?
- You'll see the specific parse error instead of a formatted result. For a dedicated pass/fail check, use the JSON Validator.
- Can I control the indentation?
- Yes — choose 2 spaces, 4 spaces, or tabs before formatting.
- Can I open a file instead of pasting?
- Yes, there's an Open file button, or you can just paste text directly into the input box.
- Is there a size limit?
- There's no server upload limit, since nothing is uploaded. Very large pasted text may be slower to format, since it all happens in your browser tab.