Format without guessing a repair
JSON uses double quotes around keys and strings. It does not allow comments or trailing commas. Format and Minify keep the original number tokens, including large integer IDs, instead of parsing them into rounded JavaScript numbers.
A worked example
{"arms":8,"active":true} formats into an object with two properties. A trailing comma after true is an error, not an instruction to remove data.
Before you use the result
Duplicate keys are kept in the text; downstream parsers may keep only the last value. This is syntax validation, not validation against a JSON Schema. Formatting runs separately from the page so large inputs do not block typing.