CSV to Excel
Convert CSV files to Excel (.xlsx) in your browser, with real numbers and dates
How to use it
- Add one or more CSV files.
- Choose how values are read and whether the first row is a header.
- Press Convert to Excel and download the .xlsx file.
Questions
How are numbers and dates handled?
Plain numbers such as 12, -3.5 and 0.25 become Excel numbers, true and false become Excel booleans, and dates written like 2024-03-31 or 2024-03-31 14:30:00 become Excel dates. Choose Keep every value as text to change nothing.
Why did 007 or a phone number stay text?
Because turning them into numbers would change them (007 would become 7). The same goes for codes such as 1e3, values with a leading +, and numbers with more than 15 digits, which Excel cannot hold exactly.
What about a value that starts with = or @?
It is stored as text and never as a formula, so a CSV file cannot run anything when you open the result.
Why are my accents wrong?
The file is probably not saved as UTF-8. The tool reads UTF-8 and UTF-16 files, and falls back to Windows-1252 (what older Excel writes), and tells you when it does.
What is the size limit?
An Excel sheet holds 1,048,576 rows and 16,384 columns, and a cell holds 32,767 characters. A bigger CSV can be cut into pieces first with Split CSV / Excel.
Are my files uploaded anywhere?
No. The work happens in your browser, on your device. Your files are not sent to a server.
Is it free?
Yes, you can use it for free. A subscription removes limits and unlocks premium tools.