Excel vs CSV: Differences and How to Convert Between Them

Excel (.xlsx) and CSV (.csv) are two ubiquitous formats for handling tabular data, but they follow very different logics. Knowing when to use one or the other — and how to move from one to the other smoothly — is a useful skill for anyone working with data tables.

CSV and Excel: two different philosophies

The CSV (Comma-Separated Values) format is a simple text file where each line represents a row and each value is separated by a comma (or semicolon). It contains no formatting, no formulas, no multiple sheets: just raw data. The Excel (.xlsx) format, on the other hand, is a full workbook that can contain several sheets, calculation formulas, colors, charts and advanced formatting.

Why convert an Excel file to CSV?

CSV is the format of choice for importing data into most systems: databases, customer relationship management (CRM) tools, e-commerce platforms, analysis scripts. Its simplicity makes it universally compatible, whereas an .xlsx file requires software capable of reading the Excel format. Converting an Excel table to CSV is therefore often a necessary step before importing data into another tool.

Why convert a CSV to Excel?

Conversely, a raw data export often arrives as CSV: an export from a database, a web tool, or a business application. To comfortably analyze this data — sorting, filtering, adding formulas, creating charts — it's far more practical to open it in Excel. CSV to Excel conversion turns this basic text file into a usable workbook.

The classic pitfall: encoding and separators

Two issues come up regularly with CSV files:

• The separator: some countries use a comma, others a semicolon (notably in France, since the comma is already used as a decimal separator). The wrong separator can make all the data appear in a single column.
• Character encoding: accents and special characters may display incorrectly ("é" instead of "é") if the file's encoding doesn't match what the opening software expects. Using UTF-8 encoding with a byte order mark (BOM) solves most of these issues with Excel.

The method, step by step

• 1. Drop your Excel or CSV file into the tool.
• 2. The data from the first sheet (or the CSV file) is read and restructured.
• 3. Download the converted file, ready to open or import.

Good to know

A CSV file only holds a single sheet of data: if your Excel workbook has several sheets, only the first one will be taken into account when converting to CSV. Likewise, calculation formulas are converted to their resulting value in the CSV, since this format can't store formulas.

In summary

Excel and CSV aren't interchangeable, but knowing how to move between them is essential for smooth data import and export. For occasional use, an online converter saves you from opening spreadsheet software just to change a file format.