Convert CSV to XLSX Online Free

Turn plain CSV data into a proper Excel spreadsheet. Columns are auto-detected, data types are preserved, and the result opens directly in Excel or Google Sheets.

Quick Answer

To convert CSV to XLSX, drop your .csv file onto the converter. Your data is parsed with PapaParse and written to an Excel workbook using SheetJS. The conversion is instant, runs in your browser, and your data stays private.

Free, no signup Files stay on your device Under 1 minute
100% browser-based
No file size limits
Works offline
No data uploaded

Convert CSV to XLSX

Drop your CSV file here to convert it instantly

Drag & drop your .csv file here, or click to browse

Your file never leaves your browser

CSV vs XLSX: Format Comparison

Key differences between the two formats

FeatureCSVXLSX
StructurePlain text, one tableBinary workbook, multiple sheets
Data typesEverything is textNumbers, dates, booleans, text
FormattingNoneFonts, colors, borders, conditional formatting
FormulasNot supportedFull formula engine
Column widthsNot definedAdjustable per column
File sizeVery smallLarger due to structure and metadata
EditingAny text editorExcel, Google Sheets, LibreOffice

When to Convert

Common scenarios where this conversion is useful

Creating reports from raw data

Transform CSV exports from databases or APIs into formatted Excel reports that stakeholders can open, sort, and filter without technical knowledge.

Sharing data with non-technical users

Excel is the universal business format. Convert your CSV data to XLSX so anyone with Excel or Google Sheets can open and work with it.

Preparing data for Excel-based workflows

Many business processes rely on Excel templates. Convert CSV data to XLSX to feed into existing Excel-based workflows, macros, or pivot tables.

Preserving numeric and date types

When CSV is opened directly in Excel, numbers may be misinterpreted as text and dates may be reformatted. Converting properly ensures correct data type handling.

How to Convert CSV to XLSX

  1. 1

    Upload your CSV file

    Drag and drop your .csv file onto the converter, or click to browse. Both comma-separated and semicolon-separated formats are auto-detected.

  2. 2

    Automatic conversion

    Your CSV is parsed, columns are detected, and the data is written into a proper Excel workbook with the correct cell types.

  3. 3

    Download the Excel file

    Click Download to save your .xlsx file. Open it in Excel, Google Sheets, LibreOffice Calc, or any compatible spreadsheet application.

Frequently Asked Questions

Yes. The converter detects numeric values in your CSV and stores them as proper numbers in Excel, so they work correctly with formulas and sorting.

Date-like values are detected and stored as Excel date cells. Common formats like YYYY-MM-DD, MM/DD/YYYY, and ISO 8601 are recognized automatically.

The parser auto-detects the delimiter. Semicolons, tabs, and pipes are all recognized in addition to commas.

Yes. Files with hundreds of thousands of rows convert successfully. Performance depends on your device's memory, but modern browsers handle multi-megabyte CSV files well.

The output is a clean, unformatted spreadsheet. The first row from your CSV becomes the first row of the Excel sheet. You can add formatting after opening in Excel.

Yes. The converter fully supports UTF-8 encoding, including accented characters, CJK characters, emojis, and all Unicode text.

Headers are treated as regular data in the first row of the spreadsheet. The converter does not add special header formatting, but you can bold the first row in Excel.

No. The converter creates the XLSX file entirely in your browser. You only need Excel (or Google Sheets, LibreOffice) to open the resulting file.

Yes. The conversion happens entirely in your browser. Your CSV data is never uploaded to any server.

Related Conversions

Ready to convert your file?

Convert CSV to XLSX instantly - free, private, no signup required.

Start Converting