Turning a CSV export into JSON your API can use

A CSV export from a spreadsheet or database tool and a JSON payload for an API look similar — both represent rows of structured data — but CSV is a flat, typeless text format, and JSON has real types. Converting between them means making a few decisions that a spreadsheet doesn't have to.

Everything in a CSV is a string until proven otherwise

CSV has no type system — every cell is just text. A cell containing 042 is the string "042", not the number 42, and a good converter has to decide whether to preserve that as a string or coerce it to a number (which would silently drop the leading zero — a real problem for zip codes, phone number prefixes, and product SKUs). The safe default is to leave ambiguous-looking values as strings and let the consumer opt into number parsing explicitly, rather than guessing and being wrong for some rows.

Header row becomes JSON keys — check for duplicates and odd characters

The first CSV row typically becomes the key names in the resulting JSON objects. Spreadsheet exports often have header rows nobody has looked at closely — trailing spaces, duplicate column names, or special characters that are valid in a spreadsheet cell but awkward as a JSON key. Worth a quick scan of the header row before converting, especially for exports built by hand rather than generated by code.

Empty cells: "", null, or omitted entirely?

CSV doesn't distinguish between "empty string" and "no value" — a blank cell is just... blank. Different converters resolve this differently: some emit "", some emit null, some omit the key from that row's object entirely. If your API treats these three cases differently (many do — "field not sent" often means "don't update this field" in a PATCH request, which is very different from "set it to empty"), check which convention your converter uses before relying on it.

Quoted fields with embedded commas and newlines

CSV's quoting rules exist specifically to let a cell contain a comma or a newline without breaking the column structure — a field like "Smith, John" stays one column because it's wrapped in quotes. A naive CSV parser that just splits on every comma will silently corrupt any row containing a quoted comma. This is the most common source of "the conversion worked for 999 rows and mangled row 743" bugs.

Our CSV to JSON converter handles standard CSV quoting correctly and runs entirely in your browser — useful for a quick sanity check on an export before you build a pipeline that assumes a particular shape.