Double-clicking a CSV often goes wrong in Excel. Accented letters turn into strange symbols, a semicolon-separated file lands in a single column, and postcodes lose their leading zeros. Converting the CSV to a real .xlsx workbook first avoids that.
Why not just open the CSV in Excel?
Excel guesses how to read a CSV from your computer's regional settings. A comma-separated file opened on a Dutch or German computer, which expects semicolons, ends up in one column. A UTF-8 file without a marker is read in the wrong encoding, so names like Müller break. An .xlsx file has no such ambiguity: once it is built correctly, it opens the same everywhere.
How is my file read?
The separator is detected from the start of the file: comma, semicolon, tab and pipe are all recognised, and .tsv files work too. The file is read as UTF-8, with or without a byte order mark. Every line becomes a row, and the sheet is named after the file.
What about numbers and leading zeros?
With store numbers as numbers switched on, which is the default, plain numbers such as 42, -7 or 1250.50 become real numbers in Excel, so you can sum and sort them. Anything else stays text, exactly as written. That includes values with leading zeros, such as postcodes, phone numbers and product codes like 007, and very long digit strings such as account numbers, which Excel would otherwise round. Numbers written with a decimal comma or thousands separators, like 1.250,50, stay as text; convert them in Excel if you need to calculate with them.
Switch the option off to keep every cell as text.
Text that starts with an equals sign is stored as text, never as a formula, so a CSV cannot run calculations when you open it.
Anything else?
The first row is made bold by default, so the header stands out. Switch that off if your file has no header row.
Is it private?
The conversion runs on our server in Germany. The file is uploaded over an encrypted connection and deleted with the workbook automatically within two hours.
What are the limits?
CSV files up to 50 MB are free without an account, within a daily allowance of 20 server jobs; Pro takes 500 MB. Excel stops at 1,048,576 rows per sheet, so extremely long files will not fit. For a folder of exports, drop up to 5 at once for free.
How to convert CSV to Excel
- Drop your .csv or .tsv file onto the drop zone.
- Keep or switch off the number and bold header options.
- Click Convert.
- Download the .xlsx file and open it.
FAQ
Does it work with semicolon-separated files?
Yes. Semicolons, commas, tabs and pipes are detected automatically.
Can I combine several CSV files into one workbook?
Not in one step. Each CSV becomes its own workbook.
Will the file open in Google Sheets and LibreOffice?
Yes. Both open .xlsx files.
Are column widths set?
No. Double-click the column borders in Excel to fit them to the content.