What does the JSON have to look like?

An array. Each item can be an object, whose keys become columns, or an array, which is written as a plain row. Anything that is not an array is rejected with a message rather than a partial result.

Where does the extra header come from?

When objects have different keys, the header is the union of all of them, in the order the keys first appear. A row that lacks one of those keys simply gets an empty cell.

Are values converted to numbers?

No. CSV cells are text, so 120 in a CSV file becomes the string "120" in JSON. Convert the types in your own code if the number matters.

CSV and JSON Converter

Direction Delimiter

First row is the header Pretty-print JSON

Input

name,city,total
Ada,Jakarta,120
Budi,Surabaya,95

Output

Going one way, each row becomes an object keyed by the header. Going the other way, the keys become the header and any key missing from a row is left empty.

About this tool

Move between the two shapes that CSV and JSON use for tabular data. Going to JSON, each row becomes an object keyed by the header; going to CSV, the keys become the header and any key a row is missing is left empty. The delimiter is detected for CSV input and can be set by hand.

Questions

What does the JSON have to look like?: An array. Each item can be an object, whose keys become columns, or an array, which is written as a plain row. Anything that is not an array is rejected with a message rather than a partial result.
Where does the extra header come from?: When objects have different keys, the header is the union of all of them, in the order the keys first appear. A row that lacks one of those keys simply gets an empty cell.
Are values converted to numbers?: No. CSV cells are text, so 120 in a CSV file becomes the string "120" in JSON. Convert the types in your own code if the number matters.

CSV and JSON Converter