Formatting (also called beautifying or pretty-printing) adds indentation and line breaks to make JSON human-readable. It does not change the data: only the whitespace.

It sorts all object property names alphabetically at every nesting level. Useful for producing consistent, diffable JSON where the order of keys doesn't matter semantically.

If your JSON is invalid, the formatter will not produce output: instead, it shows a parse error message that identifies the approximate line and column number where the problem was detected. Common JSON errors include trailing commas after the last property, single quotes instead of double quotes around strings, unescaped backslashes inside string values, and missing commas between array elements. Fix the indicated position and try again. For a dedicated validation workflow before formatting, try the JSON Validator which gives you an even more detailed error breakdown.

No enforced limit. Since the tool runs in your browser, the practical limit is determined by your device's available memory.

Never. The entire tool runs locally in JavaScript. No data leaves your browser.