| CSV | XLSX | |
|---|---|---|
| Compression | Lossless | Lossless |
| Metadata | - | - |
| Open / royalty-free | ✓ | - |
| Defined by | - | Microsoft |
| Since | - | 2007 |
| Best for | moving tables between tools | spreadsheets people will edit |
CSV
A table as plain text. Every spreadsheet and database speaks it.
XLSX
Excel's workbook: several sheets, formulas, formatting.
Questions
CSV or XLSX: which is smaller?
It depends on the content; see our measured benchmarks on the conversion pages.
Can I convert CSV to XLSX?
Yes, in your browser, nothing uploaded.
And XLSX to CSV?
Yes, as well.