Beautify vs Minify
Beautify (the live default) adds indentation and line breaks so you can actually read nested structures. Minify strips every unnecessary space, producing the smallest valid payload — ideal for API responses, config files and localStorage.
Common JSON errors this tool catches
- Trailing commas —
{"a": 1,} is invalid JSON (valid in JS, not JSON).
- Single quotes — keys and strings must use double quotes.
- Unquoted keys —
{name: "x"} fails; use {"name": "x"}.
- Comments — JSON has no comment syntax; remove
// and /* */.
Comparing two JSON payloads? Use our Text Diff Checker after formatting both with the same indentation.
Frequently Asked Questions
How do I format JSON online?
Paste your JSON into the input — it validates as you type and pretty-prints with your chosen indentation. Invalid JSON shows the exact error with line and column.
Is my JSON sent to a server?
No. Parsing and formatting run entirely in your browser — API keys and private data never leave your device.
What's the difference between beautify and minify?
Beautify adds indentation and line breaks for humans; minify strips all whitespace to the smallest valid form for production.
Why is my JSON invalid?
Most common: trailing commas, single quotes, unquoted keys, or comments. The validator points to the exact line and column of the first error.