Why your CSV uses semicolons instead of commas, and how to get the separator you need

You open a CSV and everything is crammed into the first column, with semicolons between the values. Or an app rejects your export because it expected commas. Nothing is broken: the file was saved with a semicolon as its separator, usually by Excel on a computer whose region writes decimal numbers with a comma, such as 1,5. The fix is to tell the app reading the file which separator it uses, or to save a copy with the separator the next app expects.

Why the separator changed

A CSV file is plain text: one record per line, with a separator between the values. The best-known description of the format, RFC 4180, says the fields in each record are “separated by commas”. ^{[Source 1]} It is an informational document, and it says itself that there is no formal specification and that implementations differ considerably. ^{[Source 1]} So a CSV with semicolons is common, even if it isn’t what the name promises.

Excel has a good reason to switch. When you save a workbook as a .csv file, its default separator is a comma, but when the decimal separator is a comma, Excel uses a semicolon for the list separator instead. ^{[Source 2]} Otherwise a price like 1,5 would read as two values. On Windows, the list separator is part of the region format settings. ^{[Source 2]}

That is why the same spreadsheet can be saved as name,price on one computer and as name;price on another.

Check which separator your file uses

Before changing anything, look at the file as text. Open a copy in a plain text editor such as Notepad or TextEdit and read the first two or three lines:

name;price;delivered
Widget;1,5;24.10.2026
Bracket;12,75;25.10.2026

Three things to note:

• The separator: here a semicolon between every value.
• Decimal marks: 1,5 and 12,75 use commas. That matters later, if you switch the separator to a comma.
• Quotes: a value that contains the separator, a quote or a line break should be wrapped in double quotes. ^{[Source 1]} If quotes are missing or unbalanced, fix that first, or rows will split in the wrong places.

Open a semicolon CSV correctly

In Excel

Don’t double-click the file. Import it so you can say which separator it uses:

1. In a blank workbook, go to Data → From Text/CSV and choose the file.
2. After you click Import, choose Semicolon in the list under Delimiter. The preview changes immediately, so you can see whether the columns line up. ^{[Source 2]}
3. Click Load, or Transform Data if you need to set column types first.

If you use the older Text Import Wizard instead, the delimiter is chosen in step 2. ^{[Source 2]}

In Google Sheets

1. Open a spreadsheet and go to File → Import, then choose the file.
2. Under Separator character, choose Detect automatically, or Custom and type a semicolon. ^{[Source 3]}
3. Confirm the import and check that the columns line up.

If the file uses decimal commas, check the spreadsheet’s locale under File → Settings as well: it sets the spreadsheet’s default currency, date and number formatting. ^{[Source 4]}

Get commas back

There are two ways to end up with a comma-separated file. Pick the one that changes the least.

Change the setting on your computer

First, check Excel’s own setting. Under File → Options → Advanced → Editing options, clearing Use system separators lets Excel use its own decimal separator, and Microsoft describes setting a comma there as a way to make Excel save CSV files with semicolons. ^{[Source 2]} If someone cleared that box on your computer, that may be where your semicolons come from.

The documented way to change the separator for saved files is the List separator in the Windows region settings (Formats → Additional settings). It is a global change that affects every program on your computer. ^{[Source 2]} Note what you changed, so you can set it back.

Changing settings only affects files you save afterwards. A file you already have keeps its semicolons.

Convert a copy of the file

If you only need one file with commas, convert a copy instead of changing your computer’s settings. When you do, keep two things in mind:

• Values that contain commas need quotes. In a comma-separated file, a value such as 1,5 or Lisbon, Portugal must be wrapped in double quotes, or it splits into two columns. ^{[Source 1]} A proper CSV writer does this for you. Find-and-replace of ; with , in a text editor doesn’t.
• Decimal commas stay decimal commas. Changing the separator doesn’t turn 1,5 into 1.5. If the app you import into expects points, check its import settings first, or change the number format in your spreadsheet before you export.

Check the result before you import

Open the new file as text once more and compare it with the original:

• the same number of lines, and the same number of values on every line;
• quotes around every value that contains a comma;
• numbers, dates and IDs written exactly as before.

Then import it into the app it’s meant for. If the app still puts everything in one column, it may expect a different separator again, and its import screen usually says which.

Where CSV Import Repair fits

CSV Import Repair reads your file in your browser: it isn’t uploaded. It detects whether the file uses commas, semicolons, tabs or pipes, tells you when it had to guess, and lets you choose a different separator in the file details if the guess is wrong.

When you download the checked file, the separator is a comma unless you choose semicolon, tab or pipe. Values that contain the separator are put in double quotes. The tool doesn’t change decimal marks: 1,5 stays 1,5. In columns that look like amounts, it can point out values that aren’t written as plain numbers, and you decide what to do with them. One exception: if a broken quotation mark garbles some lines and you choose to keep those lines exactly as they are, they are copied without changes, so the download keeps the file’s original separator.

Whichever route you take, keep the original file. A separator is easy to change. A value that was split in the wrong place is much harder to put back together.