Parse error on what looks like valid JSON

common culprits: trailing commas, single quotes instead of double quotes, unquoted keys, comments (`//` or `/* */`), and `undefined` values. All of these are valid in JavaScript objects but invalid in JSON.

My large numbers changed after formatting

JavaScript parsed them and lost precision. A 64-bit integer ID like `9007199254740993` becomes `9007199254740992`. If precision matters, keep those values as strings in your JSON.

The output has `\n` and `\t` in strings

those are literal escape sequences in the JSON string values. The formatter doesn't modify string contents, only the structural whitespace between tokens.

Formatting doesn't change anything

your JSON is already formatted with the selected indentation. Try switching to a different indentation style or minifying to see the difference.

The key list is empty

check that the input is valid JSON and contains object keys. Arrays of objects work; arrays of primitives like `[1, 2, 3]` do not expose keys.

I pasted JSONL (JSON Lines) and it failed

JSONL is multiple JSON objects separated by newlines, not a single JSON document. Each line is valid JSON individually, but the whole thing isn't. Parse each line separately.

JSON Formatter

Format, minify, and filter JSON by keys

Input

Output

Filter keys0 selected

Pick exact key names from the parsed JSON. Matches apply at any depth.

Paste JSON to build a selectable key list.