Excel to CSV Converter

XLSX is the default file format for Microsoft Excel spreadsheets created in Excel 2007 and later versions. The xlsx file format stores data in rows and columns using the Office Open XML standard. Each xlsx file contains one or more worksheets with cells organized in a grid structure.

An xlsx file supports formatting, formulas, charts, and multiple sheets within a single workbook. This format is widely used for business data, financial records, and personal spreadsheets. Microsoft Excel files are the standard for spreadsheet data across industries.

XLSX File Structure

An XLSX file is a compressed ZIP archive containing XML files. Inside the archive you find folders for worksheets, styles, shared strings, and metadata. The XML structure makes XLSX files readable by many applications beyond Microsoft Excel.

• Worksheets: Each sheet stored as a separate XML file with cell data and formulas
• Styles: Font sizes, colors, borders, and cell formatting definitions
• Shared Strings: Text values stored once and referenced by cells to reduce file size
• Relationships: Links between sheets, charts, images, and other embedded objects

How to Open an XLSX File

Microsoft Excel is the primary application for opening xlsx files. Free alternatives include Google Sheets, LibreOffice Calc, and Apple Numbers. Online viewers and this converter provide access without installing any software.

CSV stands for Comma Separated Values. A CSV file is a plain text file that stores tabular data with each value separated by a comma. CSV files contain no formatting, formulas, or multiple sheets.

The CSV format is universal. Nearly every application that handles data supports CSV import and export. This makes CSV the preferred format for transferring data between different programs and systems. Data export tasks rely on CSV for maximum compatibility.

CSV File Structure

A CSV file contains one record per line. Each record contains fields separated by commas. The first line often contains column headers that name each field. Values containing commas or line breaks are enclosed in quotation marks.

Example CSV structure showing headers, values, and quoted fields containing commas.

CSV Advantages

• Universal Compatibility: Opens in any text editor, spreadsheet, or database
• Small File Size: Plain text without formatting overhead
• Human Readable: View and edit content without special software
• Easy Parsing: Simple structure for programmatic processing
• Platform Independent: Works on Windows, Mac, Linux, and mobile devices

Converting xlsx to csv removes formatting and simplifies your data for import into databases, web applications, and other software. CSV files are smaller, faster to process, and compatible with more applications than xlsx files.

Use xlsx to csv conversion when you need to:

• Import data into databases: MySQL, PostgreSQL, SQLite, and other database systems accept CSV for bulk data import
• Share raw data: Send data without formatting that receivers can open in any application
• Process with scripts: Python, R, and other programming languages parse CSV with built-in libraries
• Transfer between applications: Move data from Excel to CRM systems, accounting software, or inventory tools
• Reduce file size: CSV files are smaller than XLSX, saving storage space and transfer time
• Create backups: Plain text CSV files remain readable decades after creation

This XLSX to CSV converter uses the SheetJS library, an open-source JavaScript library for parsing and writing spreadsheet files. The library runs entirely in your browser without server communication.

Conversion Process

1. Your browser reads the XLSX file as binary data
2. SheetJS parses the compressed XML structure
3. Cell values are extracted with their calculated results
4. Data rows are assembled with comma delimiters
5. Values containing commas are wrapped in quotation marks
6. The final CSV text is displayed and available for download

Data Handling

• Formulas: Converted to their calculated values, not the formula text
• Dates: Displayed in their formatted representation from Excel
• Numbers: Preserved with original precision
• Empty Cells: Represented as empty values between commas
• Special Characters: UTF-8 encoding preserves all characters

Need to convert csv to xlsx instead? The reverse conversion adds spreadsheet formatting to your plain text data. Microsoft Excel and other spreadsheet applications open CSV files and save them as xlsx with full formatting support.

How to Convert CSV to XLSX

1. Open Microsoft Excel, Google Sheets, or LibreOffice Calc
2. Use File > Open and select your CSV file
3. The import wizard appears for delimiter settings
4. Select comma as the delimiter and complete the import
5. Use File > Save As and choose XLSX format

For converting CSV data to other formats, try our CSV to JSON Converter for structured data output suitable for web applications and APIs.

Your data stays private. All conversion happens in your browser using client-side JavaScript. Your files never upload to any server. No data is stored or accessed after conversion.

How We Protect Your Data

• Client-Side Processing: The converter runs entirely in your browser. Your Excel file loads into browser memory, converts to CSV, and downloads. No server sees your data.
• No Data Storage: We do not store any files or data. When you close the browser tab, all data is cleared from memory.
• No Tracking: We do not track file contents, names, or sizes for analytics. Your conversion activity remains private.
• Open Source Library: The SheetJS library used for conversion is open source and auditable. The code is transparent and trusted by millions of users.
• HTTPS Encryption: This page loads over HTTPS, encrypting all communication between your browser and our servers.

This xlsx to csv converter is safe for sensitive business data, financial records, personal information, and confidential documents. Your files never leave your device.

This xlsx to csv converter works on Windows, Mac, Linux, iOS, and Android. The tool runs in any modern web browser with no installation required.

Desktop Browsers

• Google Chrome (version 80 and later)
• Mozilla Firefox (version 75 and later)
• Microsoft Edge (Chromium-based)
• Apple Safari (version 13 and later)
• Opera, Brave, and other Chromium browsers

Mobile Browsers

• Safari on iOS 13 and later
• Chrome on Android 8 and later
• Firefox for Android
• Samsung Internet Browser

No plugins, extensions, or downloads required. Open the page, upload your file, and convert. Works offline once the page loads.