How to use the CSV to Excel tool
- Choose one or more CSV, TSV or TXT files, or drag them onto the drop area.
- Leave the delimiter on Detect automatically, or pick comma, semicolon, tab or pipe if the guess is wrong.
- Choose one workbook with a sheet per file, or a separate .xlsx for each file, and decide whether numbers should be stored as numbers.
- Press Convert, check the preview of the first rows and download the workbook.
Worked example: a semicolon export with ZIP codes
orders.csv came from a European system and uses semicolons. It has a header row (Name, Zip, Amount) and 4 data rows. One line reads Ann;02134;12.50.
- The tool detects the semicolon and the note reads 5 rows x 3 columns, delimiter: semicolon. The header row is counted in the 5.
- 02134 is stored as text, so the leading zero survives in Excel.
- 12.50 becomes the number 12.5, so you can sum the Amount column straight away.
With a single file the download is named orders.xlsx. Untick Store numbers as numbers if every value should stay text.
Why opening a CSV directly in Excel goes wrong
When you double-click a CSV, Excel guesses the delimiter from your computer’s regional settings and converts anything that looks like a number. That is how ZIP codes lose their leading zero, long account numbers turn into 1.23E+15 and a semicolon file ends up in one column. This converter reads the file itself, picks the delimiter that splits the lines most consistently, and only turns plain numbers into numbers. Values with leading zeros, plus signs or more than 15 digits stay text, because Excel cannot store them as numbers without losing information. TRUE and FALSE become real true and false values.
Encodings, quotes and big files
Files in UTF-8, with or without a byte order mark, and UTF-16 files that start with a byte order mark are read correctly, so accents and other alphabets come through. Quoted fields with commas, doubled quotes and line breaks inside them are handled as the CSV standard describes. Conversion runs in a background worker, so a file with hundreds of thousands of rows does not freeze the page, although your device memory sets the upper limit. Excel itself stops at 1,048,576 rows per sheet.
Your files stay on your device
Your CSV files are read and converted by code running in this browser tab, in a background worker. The workbook is created in memory on your device and handed to you as a download. No row of your data is sent to a server, so customer lists and payroll exports stay private.
Frequently asked questions
How do I keep leading zeros when converting CSV to Excel?
Leave Store numbers as numbers ticked: values with leading zeros, such as 02134 or 007, are kept as text automatically. Untick it to keep every value as text.
Can I combine several CSV files into one workbook?
Yes. Add all the files and choose One workbook, a sheet per file. Each file becomes a sheet named after the file.
What if the delimiter is detected wrongly?
Pick the right one in the Delimiter menu. Comma, semicolon, tab and pipe are supported.
Are formulas created?
No. The workbook contains the values from the CSV. A value that starts with an equals sign is stored as text, not run as a formula.
Is there a row limit?
This site sets none. Excel sheets hold up to 1,048,576 rows, and very large files need enough free memory on your device.