Excel to CSV Converter

How to Use Excel to CSV Converter

Convert Excel spreadsheet files (.xlsx, .xls, .xlsm, .xlsb) to CSV (Comma-Separated Values) format with our powerful Excel to CSV Converter. Select individual sheets or export all sheets at once, choose your delimiter, and download instantly.

Quick Start Guide

1. Upload Excel File: Click to upload or drag and drop your Excel file (.xlsx, .xls, .xlsm, .xlsb)
2. Load File: Click "Load Excel File" to read the spreadsheet in your browser
3. Select Sheet: Choose which sheet to convert from the dropdown
4. Choose Delimiter: Select comma, semicolon, or tab delimiter
5. Download: Click "Download Selected" for one sheet or "Download All" for all sheets

Understanding Excel and CSV

What is Excel?

Microsoft Excel is a spreadsheet application that stores data in binary formats (.xlsx, .xls) with support for multiple sheets, formulas, formatting, charts, and macros. Excel files are feature-rich but require specific software to open.

What is CSV?

CSV (Comma-Separated Values) is a simple text format for tabular data where values are separated by commas (or other delimiters) and rows by newlines. CSV is universally supported and can be opened in any text editor or spreadsheet application.

Why Convert Excel to CSV?

• CSV is universally compatible with all platforms
• Import CSV into databases easily
• Smaller file size than Excel
• Open in any text editor or programming language
• Process with command-line tools
• Use in data analysis tools (Python pandas, R)
• Compatible with legacy systems

Conversion Process

How It Works (100% Browser-Based):

1. File Upload: Select your Excel file from your device
2. Browser Reading: File is read entirely in your browser using FileReader API
3. Excel Parsing: SheetJS (xlsx library) parses the Excel file in browser memory
4. Sheet Selection: Choose which sheet(s) to convert
5. CSV Generation: Convert selected sheet(s) to CSV with chosen delimiter
6. Download: Download CSV file(s) directly from your browser

Important: No Server Upload

• Your Excel file NEVER leaves your device
• All processing happens in your browser
• No data sent to any server
• Works completely offline after page loads

Delimiter Options

Comma (,) - Standard CSV

name,email,age
Alice,alice@test.com,30
Bob,bob@test.com,25

Use for: Standard CSV files, US/UK formats, most databases

Semicolon (;) - European Format

name;email;age
Alice;alice@test.com;30
Bob;bob@test.com;25

Use for: European Excel (uses comma as decimal separator), some databases

Tab (\t) - TSV Format

name	email	age
Alice	alice@test.com	30
Bob	bob@test.com	25

Use for: TSV files, data with commas in values, clipboard operations

Common Use Cases

1. Database Import

Convert Excel employee roster to CSV for database import:

Excel Sheet:

• Employee data with formulas
• Multiple formatting styles
• Merged cells and colors

CSV Output:

employeeId,firstName,lastName,department,salary
E001,John,Doe,Engineering,95000
E002,Jane,Smith,Marketing,85000
E003,Bob,Johnson,Sales,75000

2. Data Analysis

Export sales data from Excel to CSV for Python/R analysis:

Excel Sheet:

• Quarterly sales with charts
• Pivot tables and summaries
• Conditional formatting

CSV Output:

date,region,product,sales,units
2024-01-15,North,Laptop,15000,120
2024-01-16,South,Monitor,8500,75
2024-01-17,East,Keyboard,12000,95

3. Multi-Sheet Export

Convert all sheets in an Excel workbook:

Excel File:

• Sheet 1: January Sales
• Sheet 2: February Sales
• Sheet 3: March Sales

CSV Files:

• january_sales.csv
• february_sales.csv
• march_sales.csv

4. Legacy System Integration

Convert modern Excel reports to CSV for legacy system import:

Excel Report:

• Complex formatting
• Charts and graphs
• Multiple data ranges

CSV Output:

• Clean tabular data
• No formatting
• Ready for legacy import

Excel Features Handling

Formulas:

• Converted to their calculated values
• Formulas are evaluated, results exported
• Example: =SUM(A1:A10) becomes 150

Merged Cells:

• Only the top-left cell value is exported
• Other cells in merged range are empty
• Recommend un-merging before conversion

Multiple Sheets:

• Select individual sheet to convert
• Or download all sheets as separate CSV files
• Each sheet becomes its own CSV file

Formatting:

• Text formatting (bold, italic, colors) is lost
• Cell background colors not preserved
• Numbers exported as text values
• Dates converted to text format

Charts and Images:

• Charts are not included in CSV
• Images are skipped
• Only data from cells is exported

Hidden Rows/Columns:

• Hidden rows and columns are included in export
• Visibility settings are ignored
• All data is exported

Features

• Multiple Format Support: .xlsx, .xls, .xlsm, .xlsb files
• Sheet Selection: Choose specific sheets or export all
• Delimiter Options: Comma, semicolon, or tab
• Large File Support: Handle Excel files up to 50MB
• Multiple Sheet Export: Download all sheets at once
• Formula Evaluation: Formulas converted to values
• 100% Browser-Based: No server uploads, complete privacy
• Instant Download: Download CSV files immediately
• Offline Capable: Works without internet after page loads

Technical Details

Supported Excel Formats:

Format	Extension	Description	Supported
Office Open XML	.xlsx	Excel 2007+	✅ Yes
Excel 97-2003	.xls	Legacy binary	✅ Yes
Excel Macro-Enabled	.xlsm	With macros	✅ Yes (macros removed)
Excel Binary	.xlsb	Binary format	✅ Yes

Processing Library:

Uses SheetJS (xlsx) library for Excel parsing:

• Industry-standard library
• Supports all modern Excel formats
• Client-side JavaScript processing
• No external dependencies

Conversion Algorithm:

1. Read Excel file using FileReader API
2. Parse file with XLSX.read()
3. Extract worksheet from workbook
4. Convert to CSV using XLSX.utils.sheet_to_csv()
5. Apply selected delimiter
6. Generate Blob with CSV data
7. Trigger browser download

Performance:

• Small files (<1MB): Instant conversion
• Medium files (1-10MB): 1-3 seconds
• Large files (10-50MB): 5-15 seconds
• Processing time depends on device speed

File Size Limit:

• Maximum: 50MB per file
• Recommended: <10MB for best performance
• Large files may take longer to process
• Browser memory limitations apply

Best Practices

1. Check Sheet Names: Verify you're converting the correct sheet
2. Remove Merged Cells: Un-merge cells before conversion for better results
3. Simplify Formatting: Remove complex formatting before export
4. Test with Sample: Try a small sample first for large files
5. Choose Right Delimiter: Consider your data content when selecting delimiter
6. Validate Output: Open CSV in text editor to verify format
7. Save Original: Keep original Excel file as backup

Excel vs CSV Comparison

Feature	Excel	CSV
Format	Binary (.xlsx, .xls)	Plain text (.csv)
Multiple sheets	Supported	Single sheet only
Formulas	Supported	Values only
Formatting	Rich formatting	No formatting
Charts/Images	Supported	Not supported
File size	Larger	Smaller
Compatibility	Requires Excel/LibreOffice	Universal
Data types	Multiple types	Text only
Import speed	Slower	Faster
Human-readable	Requires software	Any text editor

When to Use Excel vs CSV

Use Excel when:

• Need multiple sheets in one file
• Require formulas and calculations
• Want formatting, colors, styles
• Need charts and visualizations
• Sharing with Excel users
• Complex data relationships

Use CSV when:

• Importing to databases
• Universal compatibility needed
• Using in programming (Python, R)
• Command-line processing
• Smaller file size required
• Legacy system integration

Common Issues and Solutions

Problem: Formula errors in CSV

Solution:

• Ensure all formulas are calculated in Excel first
• Check for #REF, #VALUE, #DIV/0 errors before converting
• Formulas are converted to their calculated values

Problem: Date format looks wrong

Solution:

• Excel dates are converted to text
• Format dates as desired in Excel before converting
• Or post-process CSV to reformat dates

Problem: Special characters appearing as boxes

Solution:

• CSV is exported as UTF-8
• Ensure your CSV reader supports UTF-8
• Open in text editor to verify encoding

Problem: Merged cells result in empty cells

Solution:

• Unmerge cells in Excel before converting
• Only top-left cell of merged range is exported
• Use "Unmerge Cells" in Excel before conversion

Problem: File too large error

Solution:

• Split large Excel file into smaller files
• Remove unnecessary sheets
• Maximum file size is 50MB
• Delete unused rows/columns to reduce size

Problem: Hidden rows still appearing

Solution:

• This is expected behavior
• Hidden rows are included in CSV export
• Delete hidden rows in Excel before converting if unwanted

CSV Import Destinations

After Converting to CSV:

Excel/Google Sheets:

• File → Open → Select CSV
• Or drag and drop CSV file

PostgreSQL:

COPY table_name FROM '/tmp/data.csv' DELIMITER ',' CSV HEADER;

MySQL:

LOAD DATA INFILE '/tmp/data.csv'
INTO TABLE table_name
FIELDS TERMINATED BY ','
ENCLOSED BY '"'
LINES TERMINATED BY '\\n'
IGNORE 1 ROWS;

Python Pandas:

import pandas as pd
df = pd.read_csv('data.csv')

R:

df <- read.csv("data.csv")

JavaScript:

const fs = require('fs')
const csv = fs.readFileSync('data.csv', 'utf8')

Browser Compatibility

Excel to CSV Converter works in all modern browsers:

• ✅ Google Chrome (recommended)
• ✅ Mozilla Firefox
• ✅ Microsoft Edge
• ✅ Safari
• ✅ Opera
• ✅ Brave

Requirements:

• JavaScript enabled
• Modern browser (2020 or newer)
• Minimum 2GB RAM recommended for large files

Privacy & Security

Your Data is Safe:

• Excel file is processed entirely in your browser
• No data uploaded to any server
• No data stored or logged anywhere
• Works completely offline after page loads
• No cookies or tracking
• 100% client-side processing

How It Works:

1. You select an Excel file from your device
2. Browser reads file using FileReader API
3. SheetJS library parses Excel in browser memory
4. CSV is generated in browser
5. Download triggered from browser
6. No network requests for file data

Best Practices for Sensitive Data:

1. Use tool in private/incognito browser window
2. Clear browser cache after use on shared computers
3. Don't process highly confidential files on public computers
4. Verify HTTPS connection (padlock icon)
5. Close browser tab after conversion complete

Quick Reference

Input Format:

• File types: .xlsx, .xls, .xlsm, .xlsb
• Maximum size: 50MB
• Upload via click or drag-and-drop

Output Format:

• File type: .csv (text file)
• Delimiter options: comma, semicolon, tab
• Encoding: UTF-8
• One CSV per Excel sheet

Conversion:

• Excel → CSV
• Formulas → Values
• Multiple sheets → Multiple CSV files
• Formatting removed
• Data preserved