How to Convert CSV to Excel Online for Free

CSV is a simple text format for tabular data, while XLSX is an Excel workbook format suited to editing, analysis, sharing, and presentation. Converting CSV to Excel is useful when you need a spreadsheet that colleagues can open and work with directly.

Open ConvertME and choose CSV to XLSX. Select the CSV file, run the conversion, and download the Excel workbook. Open the XLSX file and review headers, column boundaries, accented characters, dates, decimal values, and any rows containing commas or quotes.

A CSV file is plain text where each line is a row and a separator marks each column. For example, the lines name,city,order_id and Ana,São Paulo,00123 should become a sheet with three columns: name, city and order_id in the header row, and Ana, São Paulo and 00123 in the row below. After converting, open the XLSX and check that each value sits in its own cell and that the header row is intact.

Ready to try it? Use the CSV to XLSX converter on ConvertME and compare the result with this layout.

ConvertME maps comma-separated values to columns and reads the file as UTF-8. Many exports from Brazil, Spain, Germany, Italy and France use a semicolon instead, because the comma is the decimal mark there. If all your data lands in a single column, open the CSV in a text editor, look at the separator, and re-export it with commas before converting.

If accents look garbled, for example é shown as é, the file is not UTF-8: save it again as UTF-8. A value that contains a comma, a line break or a quote must be wrapped in double quotes, with inner quotes doubled, otherwise it splits into extra columns. Two commas in a row produce an empty cell, which keeps the following values in the right column.

Plain text has no data types, so the spreadsheet decides what each value means. A date such as 05/03/2026 can be read as 5 March or as May 3 depending on regional settings, and 1.250,50 and 1,250.50 are the same amount written with different separators. Codes with leading zeros, such as 00123, and very long numbers can be treated as numbers and lose their zeros or turn into scientific notation. Compare a few of these columns with the original CSV before sharing the workbook.

On formats: CSV stores only text and values, with no formatting, formulas or multiple sheets. XLS is the older Excel binary format, and XLSX is the current Excel workbook format, which is what CSV to XLSX produces.

A CSV may use commas, semicolons, or tabs depending on the source system and locale. Inspect the result before sharing it. If columns do not align correctly, confirm the delimiter and text encoding in the source export.

ConvertME performs supported file conversions locally in your browser. Your source file and the converted result stay on your device rather than being sent to an external conversion server.

ConvertME turns CSV files into editable XLSX spreadsheets locally in your browser without requiring an account.