JSON to CSV Converter

Convert a JSON array of objects into a CSV file instantly, in your browser.

This tool runs entirely in your browser. Your files are never uploaded to a server.

What this converter does

Serializes JSON into comma-separated text for copying into a spreadsheet or file. A top-level array produces one CSV row per item; a single top-level object is wrapped as one row. Column names come only from the first object's keys.

How to use it

Paste valid JSON into the editor and review the CSV preview generated immediately below it. Use the copy button to transfer that text to your own editor or spreadsheet workflow. This interface does not open or download files.

Worked example

The input `[{"name":"Ada","active":true},{"name":"Alan","active":false}]` yields the header `name,active` and two rows. Boolean values are serialized as the text `true` and `false`.

Columns and escaping

Only keys on the first object define the header order. Values containing a comma, double quote, or line break are enclosed in double quotes, and embedded quotes are doubled. null and missing values become empty cells.

Shape limitations

Keys that appear only in later objects are ignored. Nested objects stringify as `[object Object]`, arrays use JavaScript's comma-joined string form, and header names themselves are not CSV-escaped. Use flat objects with simple key names for reliable output.

Validate the result

Parsing proves only that the input is valid JSON. The converter does not enforce a schema, flatten nested data, preserve JSON types in CSV, choose a regional delimiter, or guarantee how Excel or another importer will interpret formulas, dates, leading zeros, or encoding.

Privacy

Conversion runs locally in the browser and Quiklio does not send the pasted JSON to a server. Clipboard history, extensions, screenshots, and spreadsheet behavior can still expose or execute untrusted content, so sanitize sensitive values and inspect cells before opening them elsewhere.

Frequently Asked Questions

Which JSON keys become CSV columns?
Only the keys of the first object define the columns and their order. Keys found only in later objects are omitted, while missing first-object keys produce empty cells.
How are nested objects, arrays, and null handled?
null and missing values become empty cells. Nested objects become [object Object], and arrays become comma-joined strings, so flatten complex data before converting it.
Can I download the CSV file directly?
No. The interface accepts pasted JSON and provides a button to copy the CSV preview. Save that text with your own editor or pass it into your spreadsheet workflow.