CSV to Excel Converter
Convert a CSV file into a proper Excel spreadsheet (XLSX). Separators are detected automatically and numbers stay numbers.
Your files stay on your device. Conversions run in your browser.
Your files stay on your device. Conversions run in your browser.
- No signup required
- Files stay on your device
- Browser-based conversion
- Fast download
- Free to use
How it works
How to convert CSV to Excel online
- 1
Upload your CSV file.
- 2
Click “Convert to Excel”.
- 3
Download your XLSX file.
Supported file types: CSV (comma, semicolon or tab separated) · No signup required
Why CSV files often look broken in Excel
When you double-click a CSV file, Excel guesses how to read it. Depending on your regional settings, all data can end up in column A, accents like ä or é turn into strange symbols, leading zeros disappear from customer numbers and long numbers turn into 1.23E+15.
PDFConvertFast reads the file carefully instead: it detects the separator and the text encoding, keeps IDs as text and only turns real numbers into numbers. The result is a clean .xlsx file that opens correctly everywhere.
Supported CSV formats
- Comma, semicolon, tab and pipe separated files.
- Quoted fields, including commas and line breaks inside a cell.
- UTF-8 and Windows (ANSI) encoded files.
- European decimal numbers like 1234,56 in semicolon separated files.
About CSV and Excel files
- CSV (Comma-Separated Values)
- CSV is a plain-text table where each line is a row and values are separated by commas, semicolons or tabs. It is the universal import and export format for shops, banks and databases. All Excel tools →
- Excel (XLSX and XLS)
- XLSX is the modern Excel spreadsheet format (Excel 2007 and newer); XLS is the older format. Both store data in rows, columns and sheets, and open in Excel, Google Sheets, LibreOffice and Numbers. All Excel tools →
Privacy: your files stay on your device
Your files stay on your device. Conversions run in your browser. PDFConvertFast never uploads, stores or reads your documents – there is no server that receives them, no account and no email address.
- Your files stay on your device
- No signup required
- Browser-based conversion
CSV to Excel – frequently asked questions
How do I convert a CSV file to an Excel XLSX file?
Choose your .csv file (.tsv and .txt work too) and click “Convert to Excel”. You get an .xlsx file with the same name and one sheet called “Sheet1”, with column widths fitted to the content. To go the other way, use Excel to CSV.
Why does all my CSV data end up in column A, and does this converter fix it?
Yes, it fixes it. Excel often guesses the wrong separator, but this converter checks the first lines of your file and picks the one that splits them most consistently: comma, semicolon, tab or pipe. Each value then lands in its own column of the XLSX file.
Can I tell the converter which separator my CSV uses?
There is no separator setting, but a first line like sep=; is respected and then removed from the data. Files ending in .tsv are always read as tab-separated. All other files use automatic detection.
Why do umlauts and accents look broken when I open a CSV, and does conversion help?
Yes. The file is read as UTF-8 (with or without BOM), and if it isn’t valid UTF-8 it is read as Windows (ANSI) encoding – the format Excel on Windows often saves. Characters like ä, é or ç then appear correctly in the XLSX. Other encodings are not detected, so save the CSV as UTF-8 if characters still look wrong.
Will leading zeros in IDs, postcodes or phone numbers be kept?
Yes. Values like 00123 or 0049 30 1234 stay text, so the zeros are not removed. Number strings longer than 15 characters also stay text, which prevents long IDs from turning into 1.23E+15.
Which CSV values become real numbers in Excel?
Plain numbers such as 1234, -12 or 1234.56 become numeric cells you can sum. In semicolon-separated files, decimal commas like 1234,56 are converted too. Values with thousands separators, currency symbols or percent signs (1,234.50, €12, 5%) stay text.
Why are dates from my CSV not recognised as dates in Excel?
Dates are kept as text exactly as written in the CSV, so 03/04/2026 is never misread as the wrong day or month. If you need real Excel dates, convert the column in Excel afterwards, for example with DATEVALUE or Text to Columns.
What if a CSV cell contains commas, quotes or line breaks?
Fields in double quotes are kept together, including commas, separators and line breaks inside them. Doubled quotes ("") become a single quote character. A multi-line address therefore stays in one Excel cell.
Is there a size or row limit for CSV to Excel?
Each CSV can be up to 50 MB and have up to 1,048,576 rows – the maximum Excel supports. Larger row counts give an error message instead of a cut-off file. An empty file is rejected with “This CSV file is empty – there is nothing to convert.”
Does my CSV leave my computer during the conversion?
No. The CSV is read and turned into an XLSX file in your browser, so contact lists or order exports are never uploaded. The file is not stored anywhere.