Opening a CSV in Excel without breaking the accents
You double-click a CSV export and Excel shows "François Müller" instead of "François Müller", postcodes have lost their first zero, and on some computers the whole row is crammed into column A. The data in the file is fine. Excel is reading it with the wrong assumptions.
Why the accents break: encoding
A CSV is plain text, and plain text has to be stored as bytes using some encoding. Today most systems write UTF-8, where "ü" takes two bytes. Older Windows programs, and Excel itself when it saves a regular CSV on Windows, often use Windows-1252, where "ü" is a single byte.
The file doesn't say which one it uses. When you double-click a UTF-8 CSV that has no marker at the start (called a byte order mark, or BOM), Excel often assumes the old Windows encoding and reads each two-byte letter as two separate characters. That is where "ü" and "ç" come from. The reverse also happens: a Windows-1252 file read as UTF-8 shows "M�ller" with a question mark in a box. In both cases the letters are still in the file. They are just being decoded with the wrong table.
The other two problems: zeros and separators
Excel also guesses what each value is. A postcode like 01234 or a phone number like 0612345678 looks like a number, so Excel stores it as a number and drops the leading zero. An ID with more than 15 digits, such as a card or account number, is shown as 1.23457E+15 and the digits after the 15th are lost, because Excel only keeps 15 significant digits.
Then there is the separator. "CSV" says comma-separated, but Excel uses the list separator from your regional settings. In countries that write decimals with a comma, such as Spain, France or Germany, that separator is a semicolon. Open a comma-separated file there and every row stays in one column. Open a semicolon file in US or UK Excel and the same thing happens the other way round.
Fixing it inside Excel
Recent versions of Excel for Windows and Microsoft 365 have an import wizard that lets you set everything by hand. Don't double-click the file. Instead go to Data, then From Text/CSV, pick the file, set File Origin to 65001: Unicode (UTF-8) and choose the right Delimiter. To keep leading zeros, click Transform Data and change those columns to Text before loading. It works, but you have to repeat it every time you get a new export, and it is easy to forget one column.
Converting the CSV to XLSX first
An XLSX file stores the text and the type of every cell, so Excel has nothing to guess. The CSV to Excel converter makes that file in your browser, without sending the CSV anywhere:
- Open CSV to Excel and click Select CSV files, or drop them on the box. You can add up to 20 at once.
- Click Convert to Excel. There are no options to set: the separator and the encoding are detected for you.
- Download the XLSX file, or all of them as a ZIP, and open it in Excel, Google Sheets, Numbers or LibreOffice.
Here is what the converter does with your data. It reads the file as UTF-8 when the bytes are valid UTF-8. If they aren't, it falls back to the classic Windows encoding for your language, which is Windows-1252 for English, Spanish, French or German. It detects whether the separator is a comma, a semicolon or a tab. Values with leading zeros and numbers longer than 15 digits are kept as text, exactly as written. Ordinary numbers become real numbers you can add up, and in a semicolon file a decimal comma such as 12,50 is read as a number too. Each column gets a width that fits its content, so nothing hides behind #####.
If you need to go the other way, for an online shop or a mailing tool that only takes CSV, Excel to CSV writes a UTF-8 file and lets you pick a comma, semicolon or tab separator.
FAQ
Can I repair a CSV that already shows ü instead of ü?
If you only opened it and didn't save, the original file is fine: close it and convert or import it properly. If you saved it from Excel after the accents broke, the wrong characters are now written into the file, and you need to get the original export again.
Why does the same CSV look fine on a colleague's computer?
Excel's guess depends on the computer's language and regional settings. A colleague with different settings may get a different separator and encoding, so the same file opens correctly for one person and broken for another.
Will dates in my CSV be changed?
The converter only turns plain numbers into numbers. A value like 03/04/2026 or 3-4 stays as text exactly as it was written, so it isn't silently swapped into a different day or month.