CSVComma-Separated Values
A plain text file where each line is a table row, with values separated by commas or semicolons. It is the most universal data exchange format.
Convert CSV to Excel
Turn your CSV files into Excel workbooks in seconds. Conversion happens in your browser, so your files are never uploaded to a server.
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CSV4E6F6D3B4D6F6E74
XLSX504B030414000600
The first bytes of a file often reveal its real format.
or drop them here. You can also paste an image (Ctrl+V).
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Files
These sample files are generated on the page. Convert them to try it out, or add your own.
How to convert CSV to Excel
- 01
Add your CSV files
Click “Choose CSV files” or drop them on the page. You can add several at once.
- 02
Check the Excel format
Excel is already selected. Numbers are recognised automatically; dates stay written as they are.
- 03
Convert and download
Click “Convert”, then download your Excel file. With several files, grab everything at once as a ZIP.
CSV to Excel: what to know
Opening a CSV straight in Excel often puts everything in a single column. Here the separator is detected among comma, semicolon, tab and vertical bar, and a “sep=;” first line is respected. Quoted fields, even those spanning several lines, stay in one cell. An opening quote that is never closed (a malformed file) is kept as text and the rest of the file is read line by line; a closing quote followed by anything other than a separator keeps the field whole, and a line with more fields than the titles line is pointed out: a message quotes the line to check. In a TSV file, quotes stay as text, unless they surround the fields the way Excel or R writes them; a field that starts with a quote that is never closed is pointed out the same way. If the first row contains only text, it is set in bold and frozen at the top of the sheet, and column widths adjust to their content.
Plain values such as 1234.5, 1234,5, .25 or −8.25 (with a typographic minus sign) become numbers: the decimal separator is worked out from each column, or failing that from the whole file, and an ambiguous value such as 1,250 is read with a decimal comma in a semicolon file, as is a comma between two digits (12,5) in a single-column file. An amount whose thousands are separated by spaces, such as 1 250,50, becomes a number too, except in a column where the point is the decimal separator. A number written 1.10 keeps both its decimals on display. Amounts with currency symbols or % signs stay as text, as do identifiers of 16 digits or more, so they don’t lose any digits (the file’s row points them out), and codes such as 3E12 or -0, except in a column that holds only numbers, where 3E12 becomes a number, which a message points out; a value that looks like a number but stays text in a column of numbers, such as 1 250.50, 250,00-, (120.00) or +40.00, is pointed out with its cells. Dates are kept as written, as text: to calculate with them, convert them with the DATEVALUE function. A cell starting with = stays as text and is never run as a formula.
CSV vs Excel: what’s the difference?
XLSXMicrosoft Excel (Office Open XML)
The Microsoft Excel workbook format since 2007. It holds one or more sheets with their numbers, dates, text and formulas.
CSV to Excel: frequently asked questions
Are leading zeros in postcodes and phone numbers kept?
Yes. A value starting with zero, such as 02134 or 07700900123, is stored as text and keeps its zeros, whereas Excel usually strips them when it opens the CSV directly. Note that a code with no leading zero, such as 10001, becomes a number, so the same column can mix text and numbers.
Accented letters in my CSV look garbled in Excel. Does converting fix it?
Usually, yes. The problem nearly always comes from a UTF-8 file that Excel reads with the Windows encoding. Formatomat recognises UTF-8 with or without a BOM, UTF-16 and the common legacy encodings (Windows-1252, ISO-8859-15, Mac OS Roman, the DOS code pages CP850 and CP437, Central European, Cyrillic including the DOS encoding IBM866, Greek, Turkish, Baltic, Arabic, Hebrew, Thai, Japanese, Chinese, Korean), then stores the text as Unicode in the workbook, so accents display correctly. A file without a BOM that isn’t UTF-8 is read as Windows-1252 when its text reads correctly that way; otherwise the encoding is guessed, a message names the one chosen, and it is then worth checking the accents. In a UTF-8 file, a line written in Windows-1252 is read as such, and a message quotes it; a stray byte or a split character becomes “�” without garbling the rest of the text, and the message quotes its line. A file in another encoding, such as Vietnamese, may be misread, so save it as UTF-8 first.
Are my CSV files uploaded to the internet?
No. The file is read and converted by your browser, on your device. Nothing is sent to a server, and nothing is kept after you close the page.
Does converting CSV to Excel reduce quality?
No. Every value is kept: numbers become real numbers, except those a spreadsheet would not keep as written, which stay as text, unchanged: a code with a leading zero (01234), a value of more than 15 digits or beyond a spreadsheet’s limits (which the row points out), or a value that looks like a number without being written like the file’s (1 250.50 among decimal commas, 250,00-), which the row points out in a column of numbers; dates stay written as they are, and the header row is set in bold.
How many CSV files can I convert?
As many as you like, for free and without signing up. Add them all, then download the results one by one or in a single ZIP. The maximum size depends on your device and browser, with a few caps that protect its memory (for example 20,000 files per archive or 5 million filled cells per workbook: see the home page FAQ); a file over one of them is not converted, and a message says so.
Does it work on iPhone and Android?
Formatomat is designed for recent browsers on computers, iPhone and Android, with no app to install. A conversion the browser cannot do (a format it cannot read or write) is refused with a message that says so.