How to Convert CSV to XLSX Online
Convert CSV to Excel spreadsheet. Free, fast, and no account required.
Drop your CSV file here
or click to browse from your device
Supports CSV · Max 250 MB
🔒 Files are processed securely and deleted immediately after conversion.
What Is CSV?
CSV is a simple text-based format for storing tabular data. Each row represents a record, and fields within a row are separated by commas (or other delimiters). CSV is widely used for data import/export between different applications.
- Database import and export
- Spreadsheet data exchange
- Report generation
- Data migration between applications
CSV stores only raw data without formulas, formatting, charts, or multiple sheets. Converting from XLSX to CSV will preserve only the data values from the first sheet.
What Is XLSX?
XLSX is the default spreadsheet format for Microsoft Excel. It supports multiple worksheets, formulas, charts, formatting, and data validation. XLSX is an XML-based format that has become the standard for spreadsheet data.
- Financial spreadsheets
- Data analysis
- Business reporting
- Project tracking
Converting CSV to XLSX creates a formatted spreadsheet with auto-sized columns and styled headers. Converting XLSX to CSV extracts raw data values only.
Why Convert CSV to XLSX?
- 1Open data in Excel with formatted columns, headers, and the ability to add formulas and charts
- 2No software installation required — convert directly in your browser
- 3No registration or personal information needed to use the service
How to Convert CSV to XLSX
- 1
Upload your CSV file
Drag and drop your CSV file into the upload area above, or click to open your file browser.
- 2
Start the conversion
Click the "Convert to XLSX" button. The conversion begins immediately and you can track progress.
- 3
Download the result
Once complete, click the download button to save your XLSX file to your device.
Privacy & Security
Your file is transmitted over HTTPS and processed in server memory only. It is never saved to disk and is discarded immediately after the converted file is returned to you.
Frequently Asked Questions
To convert a CSV file to XLSX, use the upload area on this page. Drag and drop your CSV file or click to browse your files. Once uploaded, click the "Convert to XLSX" button. The conversion will be processed and the resulting XLSX file will be available for download.
Yes. This conversion tool is completely free to use. There are no premium tiers, no watermarks applied to your output, and no limit on the number of conversions you can perform. The service is supported by advertising.
CSV (Comma-Separated Values) CSV is a simple text-based format for storing tabular data. XLSX (Microsoft Excel Spreadsheet) XLSX is the default spreadsheet format for Microsoft Excel. Converting between these formats allows you to take advantage of the strengths of each format depending on your specific needs.
The output quality depends on the formats involved. Converting from a lossy format to a lossless format does not recover lost data, but no additional quality is lost. Converting from lossless to lossy involves some data reduction to achieve smaller file sizes. Image conversions use optimized settings to maintain visual quality.
Yes. Files uploaded for conversion are processed in server memory and discarded immediately after the converted file is returned to your browser. We do not store, copy, or analyze your files. All transfers are encrypted using HTTPS.
The maximum file size is 250 MB per file. This limit applies to all format types. Most conversions complete within a few seconds for typical file sizes.