1
Upload CSVChoose the CSV file you want to convert.
2
Analyze Document
3
Convert to XLSX
4
Download XLSX
data Converter• 100% Client-Side

CSV to XLSX Converter

Convert raw CSV data into a genuine Microsoft Excel XLSX spreadsheet.

csv→xlsx

Drop CSV file(s) here, or browse

Supports single or multiple batch conversion

Private by Design

Your files are processed directly on your device using WebAssembly, HTML5 Canvas, and client-side runtimes.

No server upload No cloud copy 100% local processing
How To Convert

How to Convert CSV to XLSX

Step 1

Upload CSV

Choose the CSV file you want to convert.

Step 2

Analyze Document

Review the detected document structure and limitations.

Step 3

Convert to XLSX

Click Convert to XLSX to start reconstruction.

Step 4

Download XLSX

Download your converted XLSX document.

Frequently Asked Questions

Questions about CSV to XLSX Conversion

Is this an actual XLSX file or just renamed CSV?

This creates a genuine OpenXML binary .xlsx workbook using SheetJS parsing.

Related File Converters

Other popular conversions for data files

View all 60 tools →
xlsxcsv
data

XLSX to CSV

Extract sheets from Excel workbooks into standard CSV files.

Runs on your device
Convert
csvjson
data

CSV to JSON

Convert tabular CSV files into clean JSON objects or arrays with automatic type casting.

Runs on your device
Convert