CSV ↔ JSON Converter API

Convert CSV to JSON and JSON to CSV online. Handles quoted fields, Excel semicolon exports and ragged rows. Free, fast, no sign-up.

The CSV ↔ JSON Converter is also available as a free REST API. Send a POST request with a JSON body to https://dot.tools/api/tools/csv-json — no authentication, no API key, CORS enabled. Successful calls return { "ok": true, "result": { … } }; failures return HTTP 400 or 422 with an error body.

Request body

Field	Type	Required	Description
`mode`	"csv-to-json" \| "json-to-csv"	required	Conversion direction: CSV to JSON, or JSON to CSV.
`input`	string	required	The CSV or JSON text to convert (max 1 MB).
`delimiter`	"," \| ";" \| "tab" \| "auto"	required	Field delimiter. "auto" sniffs the first 10 records when converting CSV to JSON, and resolves to a comma when converting JSON to CSV.
`hasHeader`	boolean	required	CSV → JSON only: treat the first row as object keys. When false, rows convert to arrays of strings.
`indent`	"2" \| "4"	required	CSV → JSON only: number of spaces per indentation level in the JSON output.

Response

Field	Type	Required	Description
`output`	string	required	The converted document. Empty when the input is empty or invalid.
`valid`	boolean	required	Whether the input parsed successfully.
`error`	unknown	required	Parse error message when invalid.
`errorLine`	unknown	required	1-based physical line of the parse error when invalid.
`errorColumn`	unknown	required	1-based column of the parse error when invalid (JSON input only).

Example request

curl -X POST https://dot.tools/api/tools/csv-json \
  -H 'Content-Type: application/json' \
  -d '{
  "mode": "csv-to-json",
  "delimiter": "auto",
  "hasHeader": true,
  "indent": "2",
  "input": "name,role,level\nAda Lovelace,engineer,9\n\"Alan \"\"Al\"\" Turing\",researcher,10\nGrace Hopper,\"rear admiral, compiler pioneer\",10"
}'

Sample response

{
  "ok": true,
  "result": {
    "output": "[\n  {\n    \"name\": \"Ada Lovelace\",\n    \"role\": \"engineer\",\n    \"level\": \"9\"\n  },\n  {\n    \"name\": \"Alan \\\"Al\\\" Turing\",\n    \"role\": \"researcher\",\n    \"level\": \"10\"\n  },\n  {\n    \"name\": \"Grace Hopper\",\n    \"role\": \"rear admiral, compiler pioneer\",\n    \"level\": \"10\"\n  }\n]",
    "valid": true,
    "error": null,
    "errorLine": null,
    "errorColumn": null
  }
}

Use the free CSV ↔ JSON Converter in your browser, read the CSV ↔ JSON Converter guide, or import the full OpenAPI specification.