quialo.

JSON to CSV Converter

Paste JSON above to build a CSV.

Paste a JSON array of flat objects and get clean CSV instantly. The header row is built from the union of every key across your records, and any field containing a comma, double quote, or line break is quoted and escaped the standard way (RFC 4180). Everything runs client-side, so your data never leaves the browser.

How to use

  1. Paste a JSON array of flat objects into the JSON input box.
  2. Pick the line ending you need: CRLF for Excel and Windows, or LF for Unix.
  3. Read the CSV that appears in the output box, including the header row built from all keys.
  4. Click Copy CSV to grab the text, or Download to save it as a .csv file.
  5. If something is off, the status line explains the problem (for example, not an array, or a nested value).

Examples

  • Input: [{"name":"Ada","age":36},{"name":"Linus","age":54}] Output: name,age then Ada,36 then Linus,54
  • Input with a comma in a value: [{"city":"Paris, France"}] Output: city then "Paris, France" (the value is quoted because it contains a comma).
  • Input with uneven keys: [{"a":1,"b":2},{"a":3,"c":4}] Output header a,b,c with empty cells where a key is missing in a row.

FAQs

What shape does the JSON need to be?
A single array containing flat objects, for example [{"id":1,"name":"Ada"}]. Each object becomes one CSV row, and the keys become columns.
How are commas, quotes, and line breaks handled?
Any field that contains a comma, a double quote, or a line break is wrapped in double quotes. Double quotes inside a field are escaped by doubling them, following the RFC 4180 convention that spreadsheets expect.
What happens when objects have different keys?
The header is the union of all keys in the order they first appear. If a row is missing a key, that cell is left empty so every row stays aligned to the header.
Does it support nested objects or arrays?
No. This tool is for flat objects, so a value that is itself an object or an array is reported as an error. Flatten or stringify nested values before converting.
Is my data uploaded anywhere?
No. The conversion happens entirely in your browser. Nothing is sent to a server, so it is safe for private or sensitive data.
Why CRLF versus LF line endings?
CRLF is the safest choice for Microsoft Excel and Windows tools, while LF is common on macOS, Linux, and many data pipelines. Pick whichever your target program expects.

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