CSV to JSON Converter

1. 01Pick a directionCSV to JSON, or JSON to CSV. The inputs and options change to match.
2. 02Paste your data, or load the sampleFor CSV, check the delimiter matches your file and say whether the first row holds the column names.
3. 03Copy or downloadThe row and column count confirms the structure was read the way you expected.

• Turning a spreadsheet export into an API payloadExports arrive as CSV and APIs want JSON. This bridges them without writing a script or opening a spreadsheet.
• Making an API response readableA JSON array of objects is hard to scan. Converting it to CSV lets you open it in a spreadsheet and actually look at the data.
• Checking a file parses at allThe row and column count is a fast sanity check on whether your delimiter and header settings are right before you use the file elsewhere.

• A three-column CSVA header row of name, email, city with two data rows becomes a JSON array of two objects, each with those three keys. The counter reads 2 rows · 3 columns.
• Going back the other wayThat same array converted to CSV returns the header row followed by the two data rows. Fields containing the delimiter are quoted so the output stays parseable.

• Check the delimiter firstFiles exported in much of Europe use semicolons rather than commas. If everything lands in a single column, this is almost always why.
• Objects in, table outJSON to CSV expects an array of flat objects. Deeply nested structures have no natural table shape, so flatten them before converting.

CSV is not one format. The comma is the default in English-speaking locales, but in countries where the comma is the decimal separator, spreadsheet software exports with semicolons instead — otherwise "1,5" would split a number across two columns. Tab-separated files show up from databases and older exports. Picking the wrong one does not usually fail loudly: it succeeds and gives you a single column containing the entire row, which is why the row and column counter is displayed rather than hidden. If the column count is 1 when you expected several, change the delimiter.

With the first row treated as a header, its values become the keys of every JSON object, which is what you want almost all the time. With it off, the first row is treated as data and columns get positional names instead, which is right when the file genuinely has no header — a log export, or a fragment of a larger file. Getting it wrong in the first direction is obvious, because your first data row disappears into the key names.

Entirely in your browser. There is no upload, no server-side parsing and nothing stored, so a CSV containing customer names, email addresses or order data never leaves your device. That is a meaningful difference from converters that process server-side, because with those the sensitive file has already been transmitted by the time you see the result.

How do I convert CSV to JSON?

Paste the CSV, confirm the delimiter and whether the first row is a header, and the JSON appears immediately. You can copy it or download it as a file.

Why is everything in one column?

The delimiter does not match the file. Semicolon-separated exports are common outside the US and UK; switch the delimiter and the columns will split correctly.

Can it handle nested JSON?

JSON to CSV expects an array of flat objects, because a table has no way to represent nesting. Flatten nested structures first.

Is there a file size limit?

There is no imposed limit, but everything is held in browser memory, so very large files are bounded by your device rather than by a server quota.

Is my data uploaded?

No. The conversion runs in your browser.