CSV is the common language of data. Almost every program can read it: online stores, CRMs, accounting software, databases and analysis tools. That is why converting an Excel file to CSV is one of the most frequent office tasks. However, a careless conversion can break accented characters, change dates, merge columns or lose data from other sheets. This guide explains how to do it right.
What a CSV file is
CSV stands for *Comma-Separated Values*. It is a plain text file where each line is a row and each value is separated by a delimiter. For example:
code,product,priceA001,Office chair,89.90
Unlike an Excel file, a CSV does not store formatting, colors, formulas, charts or multiple sheets. It only stores the values of one table. That simplicity is exactly what makes it universal.
When to use CSV
- To import products into an online store such as WooCommerce or Shopify.
- To upload contacts to a CRM or email marketing tool.
- To exchange data between systems that do not share a format.
- To process data with analysis software or languages like Python.
The delimiter problem
Although it is called “comma-separated”, in countries where the comma is the decimal separator (much of Europe and Latin America) Excel often uses a semicolon as the delimiter. This causes a common problem: you create a semicolon CSV and the target system expects commas, or vice versa, and everything ends up in a single column.
Recommendation: check which delimiter the target program expects before converting. If you do not know, the comma is the international standard, but make sure decimals then use a period.
Encoding: why accents disappear
If you open your CSV and see “Café” instead of “Café”, you have an encoding problem. The file was saved in one character set and opened with another. The fix is to always use UTF-8, the standard encoding that supports accents and symbols from any language.
In Excel, choose “CSV UTF-8 (Comma delimited)” when saving. Some systems also need a BOM marker at the start of the file to recognize UTF-8; others fail if it is there. If a system shows strange characters at the start of the first column, try without the BOM.
How to convert Excel to CSV online
The easiest way to avoid these problems is to use the Excel to CSV converter on our Excel tools page. It accepts XLS, XLSX and ODS files and produces a clean CSV:
- Drag your file into the upload area.
- If the workbook has several sheets, choose which one to convert.
- Select the delimiter and encoding if the tool offers options.
- Download the resulting CSV.
It works from any browser, even if you do not have Excel installed.
Workbooks with several sheets
A CSV can only hold one table. If your workbook has three sheets, you need three CSV files or you must combine the sheets into one before converting. Always check which sheet you are exporting: saving as CSV from Excel only exports the active sheet, and it is easy to lose the rest without noticing.
Dates and numbers
Dates are the most common source of errors. A CSV stores a date as text, exactly as it appears in the cell. If the target system expects 2026-09-30 and your CSV contains 09/30/2026, the import will fail or, worse, it may read October 9 as September 10.
Tips:
- Use the ISO format (
YYYY-MM-DD) whenever the target system accepts it. - Remove thousands separators from numbers (“1,500” may be read as 1.5 in some locales).
- Remove currency symbols from price columns.
Leading zeros
Zip codes, phone numbers and product codes like “00825” must be kept as text. If the cell has a number format in Excel, the CSV will store “825”. Apply text formatting to those columns before converting.
Final check
Before importing the CSV into another system, open it with a text editor (not Excel, which reinterprets it) and check:
- That the delimiter is correct.
- That accented characters look right.
- That every row has the same number of columns.
- That there are no empty rows at the end.
- That text containing commas or line breaks is wrapped in quotes.
Frequently asked questions
Why does my CSV show everything in a single column?
Because the file’s delimiter does not match what the program opening it expects. If the file uses commas and your Excel expects semicolons (or vice versa), all the content ends up in column A. Import the file specifying the right delimiter or regenerate it with the correct separator.
Are formulas kept when converting to CSV?
No. A CSV only stores the visible result of each cell. If you need to keep the formulas, save a copy as XLSX as well.
Can I convert several sheets at once?
Each sheet must become a separate CSV, because the format only supports one table per file. If you need everything in a single CSV, first combine the sheets into one with the same column structure.
What if the target system rejects the file?
Read the error message and check, in this order, the encoding, the delimiter, the column names and the date and number format. In most cases the problem is one of those four.
Conclusion
Converting Excel to CSV is simple if you control four things: the delimiter, UTF-8 encoding, the date and number format, and the sheet you export. With the converter on our free tools page you get a clean file in seconds from any device. And if you need to go the other way, you will also find a CSV to Excel converter there.
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