Convert CSV to Excel

Turn a CSV export into a real XLSX workbook that opens straight into columns, with no import wizard, no mangled accents and no lost leading zeros.

Drop your files here

.csv, .tsv, .txt · up to 300 MB

Choose files

Column separator

More settings

Character encodingFirst row is a headerCell typesDecimal separatorOne sheet per file

How to Convert to Excel

1
Drop your CSV file
Add one file or up to twenty at once. Everything is read inside this browser tab, so even a large export never leaves your machine.
2
Check the detected delimiter and encoding
The separator and character set are worked out from the file itself. If the preview looks wrong, override either one and the result updates.
3
Convert and download the XLSX
Press the button and save the workbook. One CSV gives one XLSX named after it; several CSVs give one workbook each, with a single sheet named after its file, and all of them arrive together in one ZIP.

Why Excel puts everything in one column

Excel decides how to split a CSV using the list separator configured in your operating system, not by looking at the file. On a machine set to a European locale that separator is a semicolon, so a comma-separated file arrives as a single column of text; on a US machine the reverse happens with a semicolon file. This converter never guesses from your settings. It parses the file with each candidate separator (comma, semicolon, tab, pipe and colon) and keeps the one that yields the same field count on every sampled line. If two candidates tie, it says so instead of picking one, because a wrong split is far more expensive to undo than a question is to answer.

Leading zeros, long numbers and dates

The most damaging thing a converter can do is be too clever about types. A product code of 00123 that becomes the number 123 is not recoverable from the workbook, and a sixteen-digit card or barcode silently loses its last digits because a double cannot hold more than fifteen significant figures. Both cases stay text here, deliberately. Genuine numbers still become numbers so you can sum them, ISO dates and dd.mm.yyyy dates become real dates, and true/false become booleans. If you would rather nothing at all be interpreted, switch typing to text and every cell arrives as a string.

Windows-1251, Windows-1252 and the byte order mark

Exports from accounting systems and older databases are frequently not UTF-8. The file is checked for a byte order mark first, then decoded strictly as UTF-8; if that fails, the distribution of high bytes decides between Windows-1251 and Windows-1252. A UTF-8 mark is removed rather than passed through, which matters more than it sounds: an invisible U+FEFF glued to the first header cell means that column no longer matches any name your next tool expects.

Your export never leaves this tab

Reading the file, detecting the encoding, parsing the rows and writing the XLSX all happen locally in your browser. There is no upload, no queue and no temporary copy on a server, which is the point when the file is a customer list or a payroll export.

Frequently asked questions

Why does Excel show my CSV as gibberish?

Because the file is not UTF-8 and Excel assumed it was, or the opposite. Files from Russian accounting software are usually Windows-1251 and files from older Western systems Windows-1252. Both are detected here automatically, and the resulting XLSX stores text in Unicode, so the problem does not come back.

Why is all my data in a single column?

Excel split the file on the separator from your system settings rather than the one actually in the file. This converter detects the real separator by parsing the first lines with each candidate, so a semicolon file opens into columns even on a US-configured machine.

What is the difference between comma and semicolon files?

Nothing structural; both are CSV. Countries that use a comma as the decimal separator export with semicolons instead, so 1,50 stays a single number. If your file uses semicolons, set the decimal option to comma so those values become real numbers.

Will leading zeros survive?

Yes. A value like 00123 is kept as text rather than turned into 123, along with any number longer than fifteen digits, because phone numbers, IBANs and barcodes lose data the moment they become floating point.

How many rows can an XLSX file hold?

1,048,576 rows and 16,384 columns, a hard limit of the format itself, not of this tool. A larger CSV is refused with a clear message and a link to the CSV splitter, which cuts it into files Excel can open.

Can I combine several CSV files into one workbook?

Not into one workbook on this page. Up to twenty files can go in at once, but each becomes its own XLSX with one sheet named after the file, and they come back together in one ZIP. If the files share their columns, Merge CSV can stack them into one CSV first, which then converts into a single sheet.

Is my file uploaded anywhere?

No. Parsing and workbook writing run entirely in your browser using JavaScript and the SheetJS library. Nothing is sent to a server at any point, and closing the tab leaves no copy behind.