How to Open a CSV File in Excel Without Losing Data

Problem 1: leading zeros disappear

Excel treats 01234 as the number 1234. ZIP codes, employee numbers and product codes lose their zeros, and if you save the file again the zeros are gone for good. Import the column as text, or convert the CSV to XLSX with a tool that keeps codes as text.

Problem 2: long numbers are rounded

Excel keeps only 15 significant digits. A 16-digit card or order number such as 4111111111111111 becomes 4.11111E+15 and its last digit turns into 0. The only fix is to store such values as text before Excel converts them.

Problem 3: garbled characters

Most programs save CSV as UTF-8. If the file has no byte order mark (BOM), Excel on Windows may read it with an older encoding and show é instead of é, or question marks instead of Chinese and Japanese text. Use Data, From Text/CSV and choose 65001: Unicode (UTF-8), or convert the file to XLSX.

Problem 4: everything ends up in one column

Excel expects the list separator of your Windows region. A comma-separated file opened on a computer set to German or French ends up in column A only. Choose the delimiter when importing, or convert to XLSX, which has no delimiter problem.

The safe ways to open a CSV

• In Excel, use Data, From Text/CSV, and check the delimiter, the encoding and the column types before loading.
• Set code and ID columns to Text in the import dialog.
• Or convert the CSV to XLSX first with our CSV to Excel converter, which handles zeros, long numbers and encodings automatically.
• Keep the original CSV until you have checked the result.