Verdict: CSV wins for flat tabular data — spreadsheets open it natively and it stays compact. JSON wins the moment data nests or types matter — objects, arrays, and booleans survive intact. Spreadsheet tables go CSV; APIs and nested data go JSON.
| Criterion | CSV | JSON |
|---|---|---|
| Structure | Flat rows and columns only | Nested objects and arrays |
| Spreadsheets | Opens natively in Excel and Sheets | Needs import steps or scripts |
| Data types | Everything is plain text | Numbers, booleans, and null preserved |
| Readability | Simple and scannable for tables | Verbose but explicit |
| APIs | Rarely used as a payload | The default payload format |
| Best for | Exports, reports, tabular datasets | APIs, config, hierarchical data |
Every tool below runs entirely in your browser — your files never leave your device.
Wrap the field in double quotes — that is the CSV standard. A proper converter or spreadsheet handles quoted commas automatically; naive splitting on commas does not.
Only by flattening: nested keys become dotted column names and arrays are joined or exploded into rows. Some structure is always lost — keep the JSON original.
CSV for quick opens of flat data. For anything with types or nesting, import JSON via Power Query (or convert to a flattened CSV first) rather than fighting it.
Yes — the linked converters run entirely in your browser, so private datasets never leave your device.