Convert JSON to CSV

This strict converter takes the keys from the first object as the header, checks that every object has exactly the same keys, and then escapes commas, quotation marks, and line breaks according to standard CSV rules. Empty arrays, nested values, invalid JSON, and mismatched records produce a clear error instead of an ambiguous spreadsheet. The same deterministic conversion is available in the browser and through the API.

Prepare a uniform array of flat objects

Start with valid JSON whose top-level value is an array. Every item must be an object, and every field value must be a JSON scalar—string, number, boolean, or null. Nested objects and arrays are deliberately rejected because there is no single honest way to place a nested structure into a CSV cell. Some converters stringify nested values, while others flatten paths or multiply rows; each choice changes the meaning of the data. This tool stays predictable by requiring the tabular shape to be explicit before conversion. The array must contain at least one object, and the first object must contain at least one key. Its key order becomes the CSV column order, so arrange that first record as you want the spreadsheet to appear. JSON object key order is retained by the converter. Values may include commas, quotation marks, carriage returns, or line breaks; you do not need to escape those for CSV yourself, because the serializer handles them after the JSON has been parsed.

Understand strict header and row validation

The header row is derived only from the first object's keys. Each remaining object is then compared with that header as a complete key set. A record with a missing key fails, and a record with an extra key also fails, even if the extra value is empty or null. The order of keys in later objects does not matter: values are always emitted in the first object's column order. This strict check prevents a subtle class of export bugs. A permissive converter may create a growing union of columns, leave unexplained blanks, or shift data depending on which record introduced a property. Here, irregular input stops with an error that identifies the mismatched item. Null is allowed as an intentional flat value and becomes an empty CSV cell. Missing keys are not treated as null because absence and an explicit null can represent different states in a source system. Validate or normalize irregular records upstream, then submit the uniform result for a stable export.

Use the CSV safely in spreadsheets and pipelines

After validation, each header and value is serialized as one CSV cell. Cells containing a comma, quotation mark, carriage return, or line break are wrapped in double quotes, and quotation marks inside a cell are doubled. Numbers and booleans use their JSON text representation, while null produces an empty cell. The result contains one header row followed by one row per object, joined with line-feed characters. Because the algorithm is deterministic and does not use a network, clock, random source, model, or external service, identical input produces identical output. That makes it suitable for tests, scheduled exports, build steps, and repeatable data handoffs. In the browser, paste the JSON and copy the generated CSV without sending the data elsewhere. For automation, call the API at the published price of $0.002 per request. Save the returned CSV text with a .csv extension, then open or import it with the delimiter set to a comma.