Convert CSV to XLSX Online Free
CSV is a plain-text table format that stores rows of data separated by commas. XLSX is the modern Excel spreadsheet format for data, formulas, and charts. FileConverter turns your CSV into XLSX online in seconds - free, privacy-first, and with no software to install or account to create.
CSV to XLSX turns a plain data file into a full Excel workbook where you can add formulas, formatting, charts, and multiple sheets.
What changes when you convert CSV to XLSX
Importing CSV into XLSX gives you a proper spreadsheet where you can add formulas, formatting, charts, and multiple sheets. The raw values are placed into cells ready for analysis in Excel or Google Sheets.
About the CSV format
CSV is the lowest-common-denominator format for tabular data, importable by virtually every database, spreadsheet, and analytics tool. It stores raw values only, with no formulas, formatting, or multiple sheets. In everyday use, CSV is chosen for importing and exporting data between systems and simple data tables and mailing lists. It opens in Excel, Google Sheets, databases, and any text editor.
About the XLSX format
XLSX stores tabular data with formulas, multiple sheets, and formatting in an XML-based package. It is the standard for spreadsheets in Excel, Google Sheets, and LibreOffice Calc. In everyday use, XLSX is chosen for financial models and data tables and spreadsheets with formulas and charts. It opens in Microsoft Excel, Google Sheets, and LibreOffice Calc.
CSV vs XLSX
CSV is best known for universally importable and human-readable, while XLSX stands out for supports formulas, multiple sheets, and formatting. Choosing between them comes down to where the file needs to go next.
Common use cases
People convert CSV to XLSX for jobs such as financial models and data tables and spreadsheets with formulas and charts. It is especially common when a CSV file arrives from one system but needs to work in another that standardises on XLSX.
When to convert CSV to XLSX
Reach for CSV to XLSX when your destination expects XLSX — for example financial models and data tables and spreadsheets with formulas and charts. It is the right move when you receive a CSV file but the app, website, or person you are working with cannot use it. Bear in mind that not ideal as a fixed print layout (use PDF), so keep your original CSV if you might need it again.
How to convert CSV to XLSX
- Open the converter with CSV to XLSX pre-selected using the button below.
- Upload your CSV file (drag and drop or browse) within the size limit shown on this page.
- Confirm XLSX is selected as the target format.
- Start the conversion and download your XLSX file the moment it is ready.
Quality tips
Digital-born CSV files convert most predictably. Scanned pages need OCR before editable text looks perfect, and very complex layouts are worth a quick review in the destination app after converting to XLSX.
Platform compatibility
The CSV to XLSX converter works on Windows, macOS, Linux, Android, and iOS - anywhere with a modern browser. No plugins or permissions are required to export XLSX.
File size limits
Documents up to 200MB
Troubleshooting
- If the file exceeds the limit shown below, compress images, trim video, or split archives before retrying.
- If conversion fails, confirm the extension matches the real format — renaming a file alone does not change its contents.
- Password-protected PDFs must be unlocked before conversion.
- Heavy formatting may shift slightly — allow a minute to tidy headings in Word or a similar app.
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