CSV is plain text
A CSV contains rows of delimited text. It has no standard place for fonts, colours, charts, merged cells, data validation or multiple worksheets.
One worksheet becomes one CSV
When an XLSX workbook has several worksheets, a complete export needs several CSV files. This site packages them in a ZIP so no worksheet is silently discarded.
Delimiters and encodings vary
Commas are common, but semicolons and tabs are also widely used. UTF-8 is the safest encoding for international text. Always inspect dates and identifiers after importing because spreadsheet software may reinterpret them.
Treat formulas from strangers as data
Values beginning with =, +, - or @ can be interpreted as formulas by spreadsheet applications. A cautious CSV-to-XLSX converter stores formula-like input as literal text.
These guides are general information, not legal, security or records-management advice. Follow your organisation’s policies for sensitive files.