JSON ⇄ CSV Converter

Turn a JSON array into a spreadsheet-ready CSV, or a CSV export back into JSON. Nested objects are flattened to dot paths and quoted fields are handled correctly.

Delimiter

Arrays in JSON

First CSV row is a header Infer types (numbers, true/false, null) Rebuild nested objects from dot paths

JSON

CSV

Table preview

Convert something to see it as a table.

How nested JSON becomes columns

CSV is flat: every row has the same columns. Nested objects are flattened into dot-path column names, so {"user": {"name": "Ada"}} becomes a user.name column. The header is the union of every key in every object, in the order they first appear. A row that lacks a key gets an empty cell. Arrays are either kept as JSON text in one cell or expanded into numbered columns like tags.0 and tags.1.

Converting back with Rebuild nested objects turned on reverses this. Dot paths become nested objects again, numbered keys become arrays, and cells holding JSON arrays or objects are parsed.

Quoting rules (RFC 4180)

A field is wrapped in double quotes when it contains the delimiter, a quote, a line break, or leading or trailing spaces. Quotes inside a field are doubled: She said "hi" becomes "She said ""hi""". The parser follows the same rules, so values with commas and multi-line text survive a round trip.

Opening CSV in Excel

Excel in many European locales expects semicolons, because the comma is the decimal separator there. If all your data ends up in column A, convert again with the semicolon delimiter. Auto-detect handles either when you paste CSV in.