JSON Formatter
Format and beautify JSON with consistent indentation and optional key sorting. Perfect for readable API payloads, config files, test fixtures, and stable review output in version control.
Complete Guide: JSON Formatter
Everything you need to know about using this tool effectively
The JSON Formatter parses JSON text and outputs it with clean, consistent indentation. It validates the input for correct syntax and reports the exact line and column of any errors. You can choose the indent size and optionally sort object keys alphabetically. The tool handles minified, compacted, or poorly formatted JSON. All processing happens in the browser.
This tool uses JSON.parse to validate the input, then JSON.stringify with indentation to produce formatted output. If parsing fails, the error message includes the position where the problem was detected. Key sorting recursively sorts all object keys for stable, diffable output.
Beautifying minified JSON for debugging
Paste a minified JSON payload from a log or API response and format it for readable inspection.
Validating JSON before use
Check that a JSON string is syntactically valid before using it in code or configuration.
Sorting keys for stable diffs
Sort object keys alphabetically so JSON files can be compared cleanly in version control.
Preparing JSON for documentation
Format JSON examples with consistent indentation for inclusion in API documentation.
Paste JSON
Enter JSON text in the input area.
Set options
Choose indent size (2 or 4 spaces) and toggle key sorting.
Format
Click Format. The tool validates and reformats the JSON.
Copy the result
Copy the formatted JSON or download it as a file.
Use key sorting for JSON that will be committed to version control.
2-space indentation is the most common convention in JavaScript projects.
If the JSON has a syntax error, the tool shows the exact line and column.
The formatter handles nested objects and arrays to any depth.
Will formatting change the JSON data?
No. Formatting only changes whitespace (indentation and line breaks). The data, key order, and values are preserved exactly as entered.
What if my JSON has a syntax error?
The tool catches the error during parsing and shows the exact line and column number where the problem was detected, along with a description of the issue.
Can I sort object keys?
Yes. Enable key sorting to alphabetically sort all object keys recursively. This produces stable, diffable output.
Is my JSON uploaded to a server?
No. All parsing and formatting happens in your browser using JavaScript. The data never leaves your device.
How large can the JSON be?
The tool handles JSON of any size that fits in browser memory. Very large documents (hundreds of MB) may slow down on older devices.
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