JSON to CSV

This converts an array of JSON objects into CSV that a spreadsheet will open cleanly. Each object becomes a row and each property becomes a column, with the header taken from the union of all keys — so rows with different shapes still line up correctly, and a missing property becomes an empty cell rather than a shifted column.

Quoting and escaping are handled by PapaParse, so values containing commas, quotes or newlines are written correctly rather than breaking the file.

1. Paste a JSON array of objects. A single object is treated as one row.
2. Choose your delimiter — comma, semicolon, tab or pipe.
3. Press Convert to CSV.
4. Download the file, or copy it into a spreadsheet.

This is the honest part. CSV is a flat format and JSON is not, so any conversion of nested data involves a decision. You get two:

• Flatten to dotted columns. {"address": {"city": "London"}} becomes a column named address.city. Array items are indexed: tags.0, tags.1. This reads well in a spreadsheet, but an array of varying length produces a different number of columns per row.
• Keep as JSON text. The nested value is written into the cell as a JSON string. The structure survives intact, but the cell is not something a spreadsheet can work with.

Neither is wrong; they suit different destinations. Pick the one that matches what you will do with the file.

• Handing API data to someone who works in Excel or Google Sheets.
• Preparing a bulk import file for a system that only accepts CSV.
• Producing a quick report from a JSON export.
• Loading data into a tool that expects tabular input.

• The input must be an array of objects, or a single object. An array of bare values has no columns and is rejected with an explanation.
• Nesting is lossy in the ways described above.
• null is written as an empty cell, which is indistinguishable from an empty string once the file is read back. CSV has no null.
• Every value becomes text. Types are recovered only by whatever reads the file, and its guesses may differ from yours.
• The output uses LF line endings. Some Windows tools prefer CRLF; most now accept both.