How to open a CSV file in Excel without broken columns, characters or zeros

You download a report from a business system, a bank or an online store, double-click the .csv file, and Excel opens it all wrong: everything squeezed into column A, special characters replaced by odd symbols, leading zeros gone. The file is not corrupted. These are five well-known problems, and each one has a simple fix.

1. Everything in one column: the delimiter

CSV stands for "comma-separated values", but in practice every system picks its own delimiter: comma, semicolon, tab or pipe. When you double-click a CSV, Excel uses the list separator set in your Windows regional settings. In the US, the UK and India that is a comma, so files exported by European or Latin American systems, which usually use semicolons, open with each whole row stuck in a single cell. The reverse happens to people whose Excel uses a semicolon.

The quickest way out is to not double-click the file. In Excel, open the Data › From Text/CSV button, pick the file and check the delimiter in the preview before loading. Another option is to convert it with the CSV to Excel converter, which detects the delimiter automatically: the .xlsx it creates opens with the right columns on any computer, whatever the regional settings.

2. Garbled characters: the encoding

When "José" shows up as "José", the problem is character encoding. Modern systems export in UTF-8, but when you double-click a file Excel often reads it as Windows-1252 (Latin-1) if there is no marker at the start of the file saying it is UTF-8. The opposite also happens: an old Latin-1 CSV read as UTF-8 shows question-mark diamonds instead of accented letters.

When importing through Data › From Text/CSV, set File Origin to "65001: Unicode (UTF-8)". The I Love Office converter has an encoding option: if characters look wrong with UTF-8, switch to Latin-1 and convert again.

3. Leading zeros that disappear

ZIP codes, PIN codes, product codes, employee IDs and account numbers that start with zero are treated as numbers, and the zero is dropped: 02134 becomes 2134. When importing in Excel, set those columns to Text. The site's CSV to Excel converter does this automatically: values that start with zero are kept as text and arrive complete in the spreadsheet.

4. Long numbers in scientific notation

Excel stores numbers with at most 15 digits of precision. Card numbers, long barcodes and some reference numbers go beyond that: they show up as 4.11111E+15 and, worse, the last digits are permanently turned into zeros if you save the file. These fields must also come in as text, and the converter does that for every sequence longer than 15 digits.

5. Dates with day and month swapped

A US system exports 03/04/2026 meaning March 4; in Excel set to the UK or India, that becomes 3 April, with no warning at all. Whenever you can, ask the system for dates in year-month-day format (2026-03-04), which is never ambiguous. In the site's converter, dates in that format become real dates in the spreadsheet; dates with slashes are kept exactly as they appear in the file, so day and month are never swapped by mistake.

Quick summary

• Everything in one column: the file delimiter differs from your Excel default.
• Odd characters: encoding; use UTF-8 or Latin-1 depending on the source.
• Missing zeros and scientific notation: those fields must be imported as text.
• Swapped dates: prefer the 2026-03-04 format.

If you just need to open the file and work on it, converting the CSV to .xlsx fixes most of these problems at once, and you can send the converted file to anyone without them having to repeat the steps. For the opposite direction, creating a CSV from a spreadsheet, Excel to CSV lets you choose the delimiter.

Frequently asked questions