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.
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What is JSON Formatter?
JSON Formatter parses JSON text and outputs it with clean, consistent indentation. It validates syntax and reports the exact line and column for parse errors. You can choose the indent size and sort object keys alphabetically for stable, readable output. The tool handles minified, compacted, or poorly formatted JSON.
How does JSON Formatter work?
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.
Key Features
- Formats JSON with configurable indentation
- Validates JSON syntax with error position
- Optional alphabetical key sorting
- Handles minified and compacted JSON
- Real-time formatting with instant output
- Copy formatted JSON to clipboard
- Download as .json file
- Sorts object keys alphabetically and detects parsing errors with line numbers
Common Use Cases
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.
How to Use This Tool
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.
Pro Tips
- 1
Use key sorting for JSON that will be committed to version control.
- 2
2-space indentation is the most common convention in JavaScript projects.
- 3
If the JSON has a syntax error, the tool shows the exact line and column.
- 4
The formatter handles nested objects and arrays to any depth.
Frequently Asked Questions
Will formatting change the JSON data?
No. JSON formatter only changes whitespace such as 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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