JSON to CSV & CSV to JSON Converter

Convert JSON to CSV or CSV to JSON online. Paste or upload data, review the output, and download the converted file.

Convert a JSON array to CSV: tested example

For predictable results, use a flat JSON array of objects with the same fields in every record. The first object supplies the CSV column names. Choose JSON to CSV, paste your array into JSON Data, select Convert, review CSV Data, then select Download.

This example was checked in the live converter on October 24, 2026. It preserves zero and false and keeps a comma inside a quoted CSV value.

[{"name":"Ada","note":"red, blue","count":0,"active":false},{"name":"Lin","note":"plain","count":2,"active":true}]

Observed CSV output:

name,note,count,active
"Ada","red, blue","0","false"
"Lin","plain","2","true"

Convert CSV back to JSON

Choose CSV to JSON, paste a header row followed by data rows into CSV Data, then select Convert. For the example below, the converter returned two JSON objects. The comma in red, blue stayed inside one field. The count values became numbers and the active values became booleans.

name,note,count,active
Ada,"red, blue",0,false
Lin,plain,2,true

A separate check with id values 00123 and 00456 preserved those values as JSON strings. Review the result when identifiers or data types matter; these examples do not establish how every possible value will be interpreted.

Current limits and troubleshooting

Can this converter flatten nested JSON?

Nested objects and arrays are not reliably flattened into spreadsheet columns. In a live test, nested values produced quotes that were not escaped correctly in CSV. Convert nested data into flat scalar fields before using this tool, or use a converter that explicitly supports your nesting structure.

Why are fields missing or shown as undefined?

The JSON-to-CSV test used the first record to choose columns. A field present only in a later record was omitted, and a missing field was written as undefined. Give every object the same keys and fill missing values deliberately before converting. Keep your original data and compare the output before importing it elsewhere.

Why does my JSON show a conversion error?

JSON property names and string values need double quotes. Remove trailing commas. For example, [{"name":"Ada",}] returned a conversion error in our test; [{"name":"Ada"}] is the corrected syntax. Select the direction that matches your input and use Clear to reset the tool.

Which files and sizes should I use?

The interface accepts pasted data and offers file upload for JSON or CSV. This check covered small pasted examples. A maximum reliable file size and large-file performance have not been verified. Start with a small sample and review its output before converting a larger dataset.

Related data tools

Need to inspect a table or edit headers? Open the CSV viewer and editor. For more utilities, browse the free online tools directory.

Examples and limitations checked by WebToolBase on October 24, 2026. Tests used synthetic data, not personal or confidential records.