Format, validate and minify JSON in your browser. Invalid JSON is reported with the line and column of the error. Nothing is sent to a server.
JSON is the format most APIs speak, and it is easy to read when formatted and impossible when it arrives as one long line. This tool formats JSON with proper indentation, minifies it back to a compact single line, and validates it, telling you the exact line and column of any syntax error. Everything happens in your browser.
The most useful thing a JSON tool can do is tell you where it broke. A misplaced comma or a missing bracket in a large document is painful to find by eye. When the input is invalid, this tool reports the line and column of the problem, so you can go straight to it.
The usual culprits are a trailing comma after the last item, single quotes instead of double quotes, unquoted keys, and comments, none of which are allowed in strict JSON even though JavaScript permits some of them. If your JSON was hand-edited or copied from code, those are the first things to check.
No. Formatting, minifying and validation all run in your browser. Nothing is uploaded, which matters when the JSON contains anything sensitive.
Strict JSON does not allow trailing commas, single quotes, unquoted keys or comments. The error message gives you the line and column to check first.
Formatting adds indentation and line breaks so it is readable. Minifying strips all of that to make the smallest possible output for transmission.
No. It only changes whitespace. The actual values and structure are identical.