Why does my CSV open in one column in Excel?

Your Excel locale expects semicolons as the list separator. Convert the file to semicolons and it will open correctly.

Why not just find and replace the commas?

Because that also replaces commas inside quoted values, splitting fields that should stay whole. The file has to be parsed and rewritten.

Converters

CSV Delimiter Converter

Switch a CSV file between comma, semicolon, tab and pipe.

LiveCtrl+↵

Inputcsv0 lines · 0 chars

Outputcsv0 lines · 0 chars

Options

Input delimiter

Detected automatically unless you pick one.

New delimiter

About this tool

Changing a delimiter is not a find-and-replace. Quoting depends on which character is the separator, so values have to be re-evaluated: a value quoted because it contained a comma may need no quotes once semicolons separate fields, and a value containing a semicolon now does.

The usual reason is regional. Excel in European locales expects semicolons, because the comma is the decimal separator there, so a comma-delimited file opens as a single column.

How to use it

Paste or upload your csvDrop a file onto the input pane, use the file picker, or paste the text directly.
Adjust the options if neededThe defaults suit most input; open Options to change the behaviour.
ConvertPress Convert, or use Ctrl+Enter (Cmd+Enter on macOS).
Copy or downloadCopy the result, or download it as a .csv file.

Worked examples

Each example below is executed against this tool by the test suite, so what you see is what the tool actually produces.

Comma to semicolon with re-quoting

Input

a,b
"x;y",2

Output

a;b
"x;y";2

The value containing a semicolon is now the one that needs quoting.

What to watch for

The details that decide whether a conversion is correct, and where information can be lost without any error being raised.

Quoting is recalculated, not copied: The file is parsed with the original delimiter and rewritten with the new one, applying RFC 4180 quoting from scratch. This is why a naive search and replace corrupts files. It changes separators inside quoted values too.
Why European Excel wants semicolons: In locales where the comma is the decimal separator, Excel uses the semicolon as its list separator. Opening a comma-delimited file there puts every row in one cell. Converting to semicolons makes the file open correctly without an import dialog.
Tab output has quoting caveats: TSV has no standard quoting convention, so if a value contains a tab the columns would break. Use the dedicated CSV to TSV converter, which replaces embedded tabs and warns about it.
The input delimiter is detected: Comma, semicolon, tab and pipe are detected automatically, so you usually only need to choose the output. Set it explicitly if a file has an unusual structure that defeats detection.

Limitations

Tab output has no standard quoting; use the CSV to TSV converter for tabs.
The output delimiter must be a single character.
Processing happens in your browser, so very large inputs are bounded by available memory. Files above roughly 10 MB are handled but will feel slower, and multi-hundred-megabyte files are better suited to a command-line tool.

Questions

Why does my CSV open in one column in Excel?: Your Excel locale expects semicolons as the list separator. Convert the file to semicolons and it will open correctly.
Why not just find and replace the commas?: Because that also replaces commas inside quoted values, splitting fields that should stay whole. The file has to be parsed and rewritten.