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CSV to XLSX Converter

Convert CSV files to the modern Excel .xlsx format — free, private, and instant in your browser.

Drop your file here or click to upload

Supports CSV, TSV, TXT files up to 100MB

Tip: select multiple CSV files to combine them into one workbook, one sheet per file.

How to Convert

  1. Upload one or more CSV files, or paste your CSV data
  2. Preview the data and adjust formatting options
  3. Click Convert to generate the .xlsx workbook
  4. Download your Excel file

Features

  • Outputs standard .xlsx readable by Excel 2007+, Google Sheets, and LibreOffice
  • Combine multiple CSV files into one workbook, one sheet per file
  • Auto-fit column widths and a bold header row
  • Auto-detects the delimiter (comma, semicolon, tab)
  • Runs entirely in your browser — files never leave your device

Use Cases

  • Create a modern .xlsx workbook from a CSV export
  • Open CSV data in Excel with proper columns and headers
  • Merge several CSV files into one multi-sheet .xlsx workbook

Frequently Asked Questions

What is the difference between XLSX and XLS?

.xlsx is the modern Excel format introduced in Excel 2007 and is the right choice for almost everyone. .xls is the older Excel 97-2003 format — use our CSV to XLS converter only if you need that legacy format.

Will the .xlsx file open in Excel and Google Sheets?

Yes. The output is a standard Excel workbook that opens cleanly in Microsoft Excel, Google Sheets, LibreOffice Calc, and Apple Numbers.

Can I combine multiple CSVs into one workbook?

Yes. Select several CSV files and each becomes its own sheet in a single .xlsx workbook.

Is my data uploaded anywhere?

Never. The conversion runs locally in your browser, so your data stays private and works offline.

Related Tools

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CSV to Excel Converter

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CSV to XLS Converter

Convert CSV files to the legacy Excel .xls (97-2003) format — free and private in your browser.

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Need to convert the other way? Try our Xlsx To Csv