Skip to content

CSV to Excel converter

Turn CSV files into an Excel workbook with numbers, dates and leading zeros kept right, or Excel sheets back into CSV. Nothing is uploaded.

  • Runs in your browser
  • Nothing is uploaded
  • Free, no sign-up

or drop them here. CSV, TSV or TXT, up to 50 files, each one a sheet. Nothing is uploaded.

Paste CSV instead

Choose or paste CSV to turn it into an Excel workbook. Nothing you add leaves this page.

How it works

Each CSV file is read with the same RFC 4180 reader as the JSON to CSV converter: values in double quotes can hold commas, quotes and line breaks. The delimiter (comma, semicolon or tab) is found from the first line, and the decimal mark from the values, so 16,50 in a semicolon file is sixteen and a half. Files are read as UTF-8 unless they say otherwise or aren't valid UTF-8, in which case they are read as Windows-1252, the character set Excel on Windows saves CSV in.

Values become what they look like, but only when that is certain. Numbers, with or without thousands separators, become numbers, and TRUE and FALSE become Excel's true and false. Dates become Excel dates only when written as 2026-10-13 (with a time, optionally): 13/10/2026 could be either day-month or month-day, so it stays as you wrote it. Text that only looks like a number stays text, shown in Excel's text format: leading zeros (007), numbers longer than the 15 digits Excel keeps, and codes like 2310009E13 that Excel would read as scientific notation. Text starting with = is saved as text, so nothing in the CSV runs as a formula.

The workbook is written by this page itself as Office Open XML, the format behind .xlsx, and packed with your browser's own compression. The first row is bold and frozen when it is a header, and each column is as wide as its widest value in the first 1,000 rows, up to 60 characters.

Excel to CSV reads the workbook the same way, inside this tab. Each cell gives the value Excel saved: the result of a formula, numbers in full to the 15 significant digits Excel keeps (so 0.1 + 0.2 is 0.3), dates and times as 2026-10-13 14:30, and TRUE or FALSE. Cells merged together keep their value in the first cell. The CSV follows RFC 4180 with CR LF line ends and, unless you untick it, starts with a UTF-8 byte order mark so Excel reads accents and emoji right.

Questions

How do I convert a CSV file to Excel?

Choose the CSV file or drop it on the page, then press Download .xlsx. The workbook opens in Excel, LibreOffice, Google Sheets and Numbers with numbers as numbers, the header row in bold and kept in view, and columns sized to fit. Choose several CSV files to get one workbook with a sheet for each.

How do I keep leading zeros when opening a CSV in Excel?

Convert it here instead of opening it in Excel directly. Values with a leading zero, like 007 or the zip code 02134, are saved as text, so Excel shows them as written. Numbers longer than 15 digits, like card or order numbers, stay text too, because Excel would turn their last digits into zeros.

How do I convert Excel to CSV?

Choose Excel to CSV at the top and open the .xlsx file. Every sheet is listed with a preview; download the one you need as CSV, or all of them at once as a ZIP. Formulas give the result Excel last saved, and dates are written as 2026-10-13.

Why does Excel show my CSV in one column?

Excel splits a CSV on the list separator your computer uses, which is a semicolon in much of Europe, so a comma-separated file can land in one column, and the other way round. A workbook made here has its columns already split, whichever separator the CSV used, so it opens the same everywhere.

Limits

CSV files can hold up to 10,000,000 characters each and 20,000,000 together, in up to 50 files; a sheet holds at most 1,048,576 rows and 16,384 columns, as in Excel, and a cell 32,767 characters (longer text is cut, and the page says so). Excel files can be up to 50 MB.

Formatting in an Excel file is not carried into CSV, which can't hold it: 25% is written as 0.25 and $1,234.50 as 1234.5. Currency amounts and percentages in a CSV stay text in the workbook. Old .xls files, binary .xlsb files, OpenDocument .ods files and password-protected workbooks can't be read; save them as .xlsx first. Formulas a program saved without calculating them come out empty, and the page says how many.

Nothing is kept in the page address or saved: reloading the page clears it.

Privacy

This tool runs entirely in your browser. The files you open and what you type are never sent to a server, and nothing is stored after you close the page. See the privacy page.

Related tools