Convert CSV to Excel
Turn CSV files into a proper XLSX workbook: numbers and dates you can sum and sort, ZIP codes and long IDs left exactly as written, and a bold, frozen, filterable header row.
- Processed on your device
- No upload, no waiting
- No signup, no watermark
How it works
Add CSV files
Drop one or more .csv, .tsv or .txt files, or paste the data. Several files become sheets of one workbook.
Check the preview
The delimiter and encoding are detected for you, and every column shows the type it will get. Change anything you like.
Download
An .xlsx workbook that opens in Excel, Google Sheets, Numbers and LibreOffice.
Frequently asked questions
Why not just open the CSV in Excel?
Excel guesses every cell on its own: ZIP codes lose their leading zero, 16-digit IDs turn into 1.23457E+15, gene names like SEPT2 become dates, and a semicolon file lands in a single column. This converter decides once per column, from all of its values, and converts only when the whole column agrees.
How are dates recognised?
Column by column. 15/03/2024 and 03/15/2024 are told apart by the other dates in the same column; ISO dates, times and month names are recognised too. Dates become real Excel dates, displayed in the order you wrote them. If a column is truly ambiguous, choose day-first or month-first yourself.
My file uses semicolons and decimal commas.
Detected automatically: 9,8 becomes the number 9.8 and 1.234,56 becomes 1234.56. You can also set the delimiter and the decimal separator by hand.
Which character encodings work?
UTF-8 and UTF-16 are detected, and files saved by older Windows programs — Western and Central European, Cyrillic, Greek, Turkish, Hebrew, Arabic, Japanese, Chinese and Korean — are recognised or can be chosen, so ą, ß, Ж and 日本 come out right.
Is my data uploaded?
No. The file is read and the workbook written entirely in your browser; nothing is sent anywhere.
Can a CSV run formulas when the workbook is opened?
No. A cell that starts with = is stored as text, never as a formula, so a hostile CSV cannot execute anything in Excel. Switch off type detection and every cell is kept exactly as text.
Good to know: An Excel sheet holds at most 1,048,576 rows; longer files continue on extra sheets with the header repeated. Very large files (hundreds of MB) are limited by your device's memory.