Flatten JSON arrays into CSV with custom delimiters.
Updated
id,name,address.city,address.zip 1,Alice,NYC,10001 2,Bob,LA,90001 3,"Charlie, Jr.",Chicago,60601
Quick start
Paste JSON, pick a delimiter, copy or download the CSV — nothing leaves your browser.
Drop an array of objects (or a single object) into the textarea.
Choose delimiter, header row, nested-key flattening, line endings and whether to add a UTF-8 BOM for Excel.
Copy the CSV to clipboard or download as data.csv ready for Excel / Numbers / Google Sheets / pandas.
In-depth guide
Paste an array of JSON objects and download a clean CSV — ready for Excel, Google Sheets, or any analysis tool. Nested objects flatten with configurable separators; special characters escape per RFC 4180. Everything runs locally.
Best results come from a homogeneous array of objects, like a database query result:
[
{ "id": 1, "name": "Alice" },
{ "id": 2, "name": "Bob" }
]Mixed shapes still work — each unique key across all objects becomes a column, with empty cells where missing.
Real-world JSON has nesting. With Flatten on:
{ "user": { "address": { "city": "NYC" } } } → column "user.address.city"You can change the separator (default .) to _ or / for tools that don't tolerate dots in column names. Arrays inside an object are JSON-encoded into a single cell — turn flatten off if you want to keep raw [Object] placeholders.
No. Parsing and conversion happen entirely in your browser. Even the download is generated locally via a Blob URL.
An array of objects — like a database result set. Each object becomes a CSV row, each unique key becomes a column. A single object converts to a one-row CSV.
When 'Flatten nested objects' is on, { address: { city: 'NYC' } } becomes a column called address.city. The separator is configurable. Arrays inside objects are JSON-stringified into a single cell.
Comma is standard, but Excel in some European locales expects semicolon. Tab is best when fields may contain commas. Pipe is rare but unambiguous.
Excel ignores UTF-8 unless the file starts with a Byte-Order-Mark. Tick the 'UTF-8 BOM' option for Excel-compatible exports — most other tools tolerate it.
Yes — per RFC 4180. Cells containing the delimiter, quotes or newlines are wrapped in double-quotes; embedded quotes are doubled. Output works with Excel, Numbers, Google Sheets, and pandas.
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