JSON to CSV Converter API

About the JSON to CSV Converter API

A JSON to CSV converter API: use it to convert JSON into CSV from any backend, script or no-code tool with a single POST request. Send an array of JSON objects and get back the CSV text, the list of columns it found, and the row and column counts. Objects do not need to share the same keys: every key that appears anywhere becomes a column, and missing values are left empty.

This is the step between an API response or database export and a spreadsheet, a finance import, or a report someone opens in Excel. You can pick a comma, semicolon or pipe delimiter to match the receiving system, and drop the header row when you are appending to an existing file. Values that contain the delimiter, quotes or line breaks are quoted so the file opens cleanly. Requests are limited to 500KB.

The Free plan and paid plans run the same JSON to CSV conversion and return the same fields.

How it works

The converter scans every object in json and collects the union of their keys in order of first appearance. That list becomes columns, so the column order follows the first object that introduced each key. Each object is then written as one row in that column order; a key that is missing, null or undefined produces an empty cell. Rows are joined with \n line endings.

Values are converted with JavaScript string conversion. Numbers and booleans come out as written, an array becomes its items joined by commas, and a nested object becomes the literal text [object Object], so flatten nested structures before sending them. A value is wrapped in double quotes when it contains the delimiter, a double quote, a newline or a carriage return, and embedded quotes are doubled, following the usual CSV convention.

delimiter defaults to a comma. include_header defaults to true; set it to false to get data rows only, while columns and column_count are still returned. row_count is the number of objects in the array. The request must carry a Content-Length header and the body may not exceed 512,000 bytes; larger bodies get a 413. An empty array is rejected as a missing parameter.

What people use it for

Data Export

Convert API JSON responses to CSV format for importing into Excel, Google Sheets, or databases

Report Generation

Transform JSON data into CSV reports for business intelligence tools and data analysis

Legacy System Integration

Convert modern JSON APIs to CSV format for compatibility with legacy systems

Data Backup

Export JSON datasets to CSV format for archival and backup purposes

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON

Default REST response

XML

Markup format

YAML

Human-readable

CSV

Tabular export

Beta

GraphQL

Query language

New

MCP

For AI agents

Request parameters — POST /v1/jsontocsv

Sent as JSON in the request body. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

Optional

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curl -X POST "https://api.apiverve.com/v1/jsontocsv" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"json":[{"name":"John Doe","age":30,"city":"New York"},{"name":"Jane Smith","age":25,"city":"Los Angeles"}],"delimiter":",","include_header":true}'

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Response — POST /v1/jsontocsv

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

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{
  "status": "ok",
  "error": null,
  "data": {
    "row_count": 2,
    "column_count": 3,
    "columns": [
      "name",
      "age",
      "city"
    ],
    "csv": "name,age,city\nJohn Doe,30,New York\nJane Smith,25,Los Angeles"
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

What a call costs — 1 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Zero-code embed — one snippet, no backend

Drop an interactive JSON to CSV Converter form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.

Changelog — JSON to CSV Converter API

Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.

Currently v1