Convert nested JSON to CSV

I see a post Convert nested JSON to CSV or table, the poster have JSON data like this:
menu1.json

 {"menu": {
  "id": "file",
  "value": "File",
  "popup": {
    "menuitem": [
      {"value": "New", "onclick": "CreateNewDoc()"},
      {"value": "Open", "onclick": "OpenDoc()"},
      {"value": "Close", "onclick": "CloseDoc()"}
    ]
  }
}}

He want to convert it to CSV or table like this:

I use Data File Converter to do this, in a minute.

Just open JSON file in DataFileConverter, and set options like this:

And then “Next” and “Next”, convert, get the output CSV file.

JSON → CSV reference

Type mapping

Value kind	in JSON	in CSV
Int	1234 (number)	1234
Decimal	1234.56 (number)	1234.56
Float	1.234e10 (number)	1.234e+10
Text	"text" (string)	quoted only when it contains a comma or a quote
Long text	"multi-line\ntext" (escaped newline inside a string)	must be quoted; line breaks inside force multi-line records
Date	"2026-09-18" (string)	2026-09-18
Datetime	"2026-09-18T14:30:00Z" (string)	2026-09-18 14:30:00
Binary	"base64:..." (string)	not representable - base64 or hex string
Boolean	true / false (boolean)	TRUE / FALSE, or 1 / 0 depending on the writer
JSON	nested object or array, kept as structure	the whole JSON value quoted, with internal quotes doubled

Dialect differences

Both JSON and CSV are file formats, so what differs below is how each one chooses to represent a value.

Property	in JSON	in CSV
identifiers	Double quotes; backslash escapes	Double quotes; a literal quote is doubled ("" )
dates	No date type: dates arrive as strings and the reader must p...	Conventional text: 2026-09-18 or 2026-09-18 14:30:00
binary	Not supported natively - base64 inside a string	Not supported
separator	Braces and commas	Comma ","
encoding	UTF-8 by definition	No declaration - UTF-8 works only with a BOM
typing	string, number, boolean, null, object, array - no date type	None - every field is text
shape	Nested objects and arrays	Flat table, optional header row
ceiling	Whole document is usually parsed into memory	No formal limit; row count bounded by memory

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