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CSV to Excel

One sheet, typed cells, header row frozen and column widths sized to content.

  • 100% local conversion
  • No file uploads
  • Preserves structure
  • Supports large files
Example Output
Sheet1
name | role
Ada  | Engineer

Convert CSV to Excel →

Convert CSV to Excel Drop a spreadsheet, pick an output format, and download the result. Everything runs in your browser — the file never leaves your machine.
info Supports CSV, TSV, TXT • Max file size: 100 MB
Convert to:

More formats coming soon

Also: Excel to CSV

Upload an .xlsx or .xls file and download the first sheet as a CSV.

CSV to Excel Conversion: Options, Tips, and Use Cases

Excel remains the dominant spreadsheet application in business environments, and many tools and workflows expect .xlsx files rather than plain CSV. Converting a CSV to Excel with ConvertRow produces a properly formatted .xlsx file complete with typed cells, a frozen header row, and column widths calibrated to your data — far more useful than simply renaming a .csv file to .xls.

The conversion uses SheetJS (xlsx.js), a widely used open-source library that creates genuine Excel workbooks. Each CSV row becomes a spreadsheet row, numeric cells are stored as numbers rather than text, and date-formatted strings are converted to Excel date values where detected. The frozen header row means collaborators can scroll through thousands of rows without losing track of column names.

Everything runs in your browser. SheetJS processes your CSV locally — no file is uploaded, no server is involved, and no account is required. The resulting .xlsx file is assembled in memory and downloaded instantly when conversion finishes.

For best results, ensure your CSV uses UTF-8 encoding and that numeric values are not padded with leading zeros (unless those zeros are intentional, like zip codes). If your data has mixed types in a column, Excel will apply its own type inference — consider formatting those columns after opening the file.

Common use cases for CSV to Excel conversion:

  • Sharing data exports with colleagues who work in Excel
  • Importing a database export into Excel for pivot-table analysis
  • Preparing a client deliverable in a standard business format
  • Combining multiple CSV exports into one Excel workbook manually
  • Feeding a downstream process that requires .xlsx over .csv

Frequently Asked Questions

Yes. SheetJS detects numeric values and stores them as Excel number cells rather than text. This means you can immediately apply formulas, sorting, and filtering to numeric columns without reformatting.

Yes. The converter applies a freeze pane to the first row so your column headers stay visible when you scroll down through large datasets in Excel or Google Sheets.

Yes. The .xlsx format produced by SheetJS is compatible with Google Sheets, LibreOffice Calc, Numbers on macOS, and all versions of Microsoft Excel. It is a standard Open XML workbook.

ConvertRow reads your CSV as UTF-8 by default, which covers the full range of Unicode characters including accented letters, Chinese characters, and emoji. If your CSV was saved in a legacy encoding like ISO-8859-1, re-save it as UTF-8 in a text editor first.

Excel supports up to 1,048,576 rows per sheet. For CSVs larger than that, only the first million rows will fit in a single sheet — but virtually all real-world exports are well under this limit.