JSON Formatter
Format, validate and minify JSON with clear error positions.Developer ToolsJSON formatter
Paste JSON to pretty-print or minify it. Parsing happens locally, so nothing is sent anywhere.
About this tool
A focused JSON workbench: paste data, choose an indent size, and get either a readable document or a compact one. Invalid input is reported with the character position from the parser instead of a generic failure.
How to use the JSON Formatter tool
- Paste your JSON. Type or paste JSON into the input area. Whitespace is fine; the parser handles it.
- Choose an indent. Pick an indent of 2 or 4 spaces, or enable Minify for a single-line result.
- Format and copy. Click Format JSON. Valid input appears in the output panel; invalid input shows the parser error. Use Copy to take the result with you.
Supported formats
Input
- JSON text
Output
- Formatted JSON
- Minified JSON
- Validation errors with positions
Inputs are validated before anything is processed. Invalid values and unsupported files are rejected with a clear error instead of failing silently.
Frequently asked questions
Does it validate as well as format?
Yes. Clicking Format JSON parses the input; if it is malformed, the parser's error message is shown instead of an empty result.
Are numbers or key orders changed?
No. Only whitespace is added or removed. Values, number representations and key order are preserved exactly as parsed.
Is there a size limit?
The input is held in browser memory, so extremely large documents are limited by your device rather than by an arbitrary cap.
Is my data sent anywhere?
No. Parsing and formatting use the browser's own JSON parser and nothing is transmitted.
Privacy
Everything you enter stays in this browser tab. There is no upload endpoint for tool inputs, no account, and no server-side copy of your text or files. Results are produced locally and disappear when you close the page.
No account is required and no file is ever uploaded. See the privacy policy for details about analytics and the limited data this site stores.
Known limitations
- JSON with comments or trailing commas is not valid JSON and will be rejected.
- Very large documents are limited by the memory available to the browser tab.
- Key order is preserved as written, but duplicate keys follow standard JavaScript parsing behaviour.
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