CSV Opens in One Column in Excel: Why, and How to Fix It

Fix 1: convert the CSV to an Excel workbook

Your CSV separates values with one character (usually a comma) and Excel is expecting another (usually a semicolon), so it sees each line as a single value. The fastest fix is to convert the CSV to an Excel workbook: Filembly's CSV to Excel converter detects whether the file uses commas, semicolons, tabs or pipes and puts every value in its own column.

1. Open the CSV to Excel converter.
2. Upload your .csv file.
3. Click Convert and download the .xlsx file.
4. Open it in Excel: the columns are already split, accents are intact and leading zeros are kept.

Why it happens: commas, semicolons and your region

CSV stands for comma-separated values, but there is no single CSV standard in practice. In Brazil, Spain, much of South America, Germany, France, Italy, Turkey, Indonesia and many other regions, the comma is the decimal separator (1,5 instead of 1.5). Using it to separate columns as well would be ambiguous, so Excel in those regions uses the semicolon as its list separator, both when it saves a CSV and when it opens one.

So a CSV exported by an American system, a web app or a script (commas) opens in one column on a computer set to Portuguese or Spanish, and a CSV exported by Excel in Brazil (semicolons) opens in one column in the United States. The data is fine; only the separator differs.

Fix 2: import the file with Excel's Data tab

Instead of double-clicking the CSV, import it. Excel then asks which separator to use.

1. Open a blank workbook in Excel.
2. Go to Data → From Text/CSV and pick your file.
3. In the preview, set Delimiter to Comma or Semicolon, whichever splits the columns correctly.
4. Set File Origin to 65001: Unicode (UTF-8) if accents look wrong.
5. Click Load.

Fix 3: split the column that's already open

If the data is already sitting in column A, select that column, go to Data → Text to Columns, choose Delimited, tick the separator your file uses (comma or semicolon) and finish. This works in every Excel version but has to be repeated for each file.

Accents look broken (é, ç, ã)

Garbled accents are a second, separate problem: the file is saved as UTF-8 but Excel read it with an older Windows character set. Importing through Data → From Text/CSV with UTF-8 selected fixes it. Converting to XLSX also fixes it, because Filembly reads both UTF-8 and older Windows-encoded files and the workbook stores text without any encoding ambiguity.

Leading zeros and dates disappear

When Excel opens a CSV directly it guesses each value's type, so postcodes like 01310-100 or 00123 lose their zeros, long ID numbers turn into 1.23E+19, and 03/04 may become a date in the wrong month. Importing with Data → From Text/CSV and setting those columns to Text prevents it.

Filembly's converter keeps values with leading zeros and long digit strings as text, reads decimal commas correctly in semicolon files (1.234,56 becomes the number 1234.56), and only converts unambiguous ISO dates (2026-10-01), leaving everything else exactly as written.

Saving a CSV the other system will accept

When an import form or platform rejects your CSV, check which separator it expects. Most web platforms, databases and scripts expect commas and UTF-8. In Excel, File → Save As → CSV UTF-8 (Comma delimited) produces that on most systems, though Excel in semicolon regions may still use semicolons. Converting your XLSX to CSV with Filembly always produces a comma-separated UTF-8 file that also opens with correct accents in Excel.