JSON to CSV Converter

An API hands you back JSON, and someone on your team just wants to open it in Excel. That request is simpler to say than to do, because JSON can nest objects inside objects and pack arrays inside those, while a spreadsheet only understands flat rows and columns.

Converting JSON to a spreadsheet

1. Paste or upload the JSON array you want to convert.
2. Let the tool flatten nested objects into dotted column names, such as address.city.
3. Check how array values inside each record are handled — usually joined into one cell or expanded into extra columns.
4. Convert and review the header row before you trust it.
5. Download the CSV and open it in Excel, Sheets or a database import tool.

Why flattening is the whole problem

A row in a spreadsheet is rectangular: fixed columns, one value per cell. A JSON record is not — it can nest three objects deep and hold an array of an arbitrary length inside any of them. There is no lossless, universally agreed way to squeeze that shape into a grid.

The standard compromise is dot notation. {"address": {"city": "Turin", "zip": "10100"}} becomes two columns, address.city and address.zip. It works well for nested objects. It works far less well for arrays, because an array can have a different length on every record, and a spreadsheet needs the same columns on every row.

What typically happens to an array field

• A short array of strings, such as tags, gets joined into one cell with a separator like a semicolon.
• An array of objects sometimes gets serialised back into a raw JSON string inside a single cell, which is honest but not pretty to read.
• Some converters expand a small, fixed-length array into numbered columns like colors.0, colors.1.
• A record with an empty array produces an empty cell, indistinguishable from a missing field once it is in CSV.
• None of these is wrong exactly — they are different trade-offs, and you should know which one your export made.

JSON to CSV questions