CSV to Excel Converter – Free Online CSV/TSV to XLSX

Convert CSV or TSV text to Excel (.xlsx) files. Multi-sheet support, custom headers, auto column width. 100% browser-based.

Features

📊

Create multiple sheets from different CSV/TSV data in one Excel file.

📝

Optionally treat the first row as headers with customizable styling.

❄️

Enable frozen header row for easy scrolling in Excel.

📏

Automatically adjusts column widths based on content.

🔒

Uses xlsx library locally. Your CSV data never uploaded.

🎨

Customize header row with bold text, background color, and font color.

Drag and drop CSV files, paste text directly, or choose multiple files for multi-sheet output.

Set delimiter (auto, comma, semicolon, tab), header options, and sheet name.

Preview the data with row/column counts before generating.

Download the generated .xlsx file.

What delimiter does it auto-detect?

The tool automatically detects comma, semicolon, or tab delimiters by analyzing the first few lines of your data.

Can I create multiple sheets?

Yes. Upload or paste multiple CSV files to create a multi-sheet Excel workbook. Each file becomes a separate sheet.

Is my data sent to a server?

No. The xlsx library runs entirely in your browser. Your CSV data never leaves your device.

What Excel features are supported?

Multiple sheets, custom headers with styling, frozen rows, auto column width, and all standard xlsx features.