CSV File Format Explained

Excel guessed the wrong delimiter, usually because the file uses semicolons while the system locale expects commas. Use Data → From Text/CSV and pick the delimiter, or open the file in LibreOffice which asks first.

CSV keeps them; the spreadsheet drops them when it converts the text to a number. Import the column as text, or quote the values and prefix them with an equals sign and quotes when generating the file for Excel.

UTF-8 is the safe default today. Older versions of Excel expect a byte-order mark to detect UTF-8, so files without it may show accented characters wrongly; LibreOffice and Google Sheets handle both.

No. A CSV file is exactly one table. Workbooks with several sheets export to several CSV files or to XLSX.

An Excel worksheet holds at most 1,048,576 rows, and Excel warns that the rest of the file was not loaded. You can load the file through Data, From Text/CSV and send it to the Data Model instead of a sheet, which avoids the row limit for analysis. Alternatives are a database such as SQLite, a script in Python or R, or command-line tools. Splitting the file into smaller parts also works.

Both are plain-text tables with one row per line. CSV separates fields with a comma, or with a semicolon in some locales. TSV separates them with a tab character. Since tabs rarely appear inside real data, TSV seldom needs quoting, which makes it easier to parse with simple tools. Commas, on the other hand, appear often in names, addresses and numbers. Spreadsheets open both formats, though you may have to choose the delimiter when importing.