CSV ↔ JSON Converter

Convert CSV to JSON or JSON to CSV. Set the delimiter and header row, control nested-object flattening, then copy or download the converted data.

Mapping and limits

Local conversion: UTF-8 input up to 1 MB, 10,000 rows and 200 columns. CSV cells remain strings; blank or duplicate headers and inconsistent rows are rejected. JSON null/missing values become empty cells. Nested objects flatten to dotted paths or stay JSON text; types are not reconstructed. Auto treats { or [ as JSON, otherwise CSV.

Input

Advanced settings

Output

Run Convert to generate output.

CSV ↔ JSON Converter

Turn a CSV table into JSON records for an API fixture, or export JSON data as CSV for a spreadsheet. With a header row, column names become object keys. CSV values remain strings: an id cell containing 001 becomes "001", not the number 1. Blank or duplicate headers and rows with different column counts are rejected.


When converting JSON to CSV, null and missing values become empty cells. Nested objects can be flattened to dotted paths or stored as JSON text; converting back does not reconstruct the original types or nesting. Input is limited to 1 MB of UTF-8 data, 10,000 records and 200 columns. Auto mode treats input starting with { or [ as JSON and other input as CSV; select an explicit mode if that is not what you intend.

Features

  • Convert CSV and JSON in either direction, with an automatic mode.
  • Select a delimiter, quote/escape characters and whether a header row is present.
  • Keep CSV cells as strings; choose how nested JSON objects become columns.
  • Set key order, indentation, LF/CRLF and optional UTF-8 BOM for the output.

How to use

  1. Select the direction and paste the source. For CSV, try an id header followed by a row containing 001.
  2. Set the delimiter and header option. For JSON to CSV, choose whether to flatten nested objects.
  3. Convert and inspect the result. In the example, the id value should remain the string "001".
  4. Copy or download the output. Check empty cells and flattened fields before importing it elsewhere.