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How to Change CSV Formatting: Format Modification Guide

Learn how to change CSV file formatting including delimiters, encoding, data types, and structure. Discover methods to modify CSV format for different applications and requirements.

RowTidy Team
Nov 25, 2025
13 min read
CSV, Formatting, Data Transformation, File Conversion, Delimiters

How to Change CSV Formatting: Format Modification Guide

If you need to change CSV formatting for different applications, systems, or requirements, you need methods to modify delimiters, encoding, structure, and data formats. 65% of data professionals need to change CSV formatting when working with multiple systems.

By the end of this guide, you'll know how to change CSV formatting—modifying delimiters, encoding, data types, and structure to meet specific requirements.

Quick Summary

  • Change delimiters - Convert between comma, semicolon, tab, and other delimiters
  • Modify encoding - Convert between UTF-8, Windows-1252, and other encodings
  • Transform data types - Change how data is formatted and represented
  • Restructure format - Modify column order, headers, and structure

Common CSV Formatting Changes Needed

  1. Delimiter changes - Comma to semicolon, tab to comma, etc.
  2. Encoding conversion - UTF-8 to Windows-1252, ASCII to UTF-8
  3. Date format changes - MM/DD/YYYY to YYYY-MM-DD, etc.
  4. Number format changes - Decimal separator, thousands separator
  5. Header modifications - Change header names, add/remove headers
  6. Column reordering - Rearrange columns in different order
  7. Quote style changes - Add/remove quotes, change quote character
  8. Line ending changes - Windows (CRLF) to Unix (LF)
  9. Data type conversions - Text to numbers, numbers to text
  10. Structure modifications - Add/remove columns, change layout

Step-by-Step: Change CSV Formatting

Step 1: Change CSV Delimiter

Modify the character that separates columns.

Change Comma to Semicolon

Method 1: Excel Save As

  1. Open CSV in Excel
  2. File > Save As
  3. Choose location
  4. File type: CSV (Semicolon delimited) (*.csv)
  5. Click Save
  6. Delimiter changed to semicolon

Method 2: Find and Replace

  1. Open CSV in text editor
  2. Press Ctrl+H (Find & Replace)
  3. Find: , (comma)
  4. Replace: ; (semicolon)
  5. Important: Only replace commas that are delimiters, not in data
  6. Click Replace All (carefully)
  7. Save file

Method 3: Power Query

  1. Data > From Text/CSV
  2. Select CSV file
  3. Click Transform Data
  4. Change delimiter in preview
  5. Home > Close & Load
  6. Save as CSV with new delimiter

Step 2: Change CSV Encoding

Convert file encoding for compatibility.

Convert to UTF-8

Method 1: Text Editor

  1. Open CSV in text editor (Notepad++, VS Code, etc.)
  2. File > Save As (or Encoding > Convert to UTF-8)
  3. Choose UTF-8 encoding
  4. Save file
  5. Encoding converted

Method 2: Excel Import/Export

  1. Open CSV in Excel using Import Wizard
  2. Select UTF-8 encoding
  3. Import data
  4. File > Save As > CSV UTF-8
  5. Encoding changed to UTF-8

Method 3: Command Line (PowerShell)

Get-Content input.csv -Encoding Default | Set-Content output.csv -Encoding UTF8

Step 3: Change Date Format

Modify how dates are formatted in CSV.

Convert Date Format in Excel

Method 1: Text to Columns

  1. Open CSV in Excel
  2. Select date column
  3. Data > Text to Columns
  4. Choose Date format
  5. Select current format (e.g., MDY)
  6. Click Finish
  7. Format cells as desired date format
  8. Save as CSV

Method 2: Formula Conversion

=TEXT(A2, "YYYY-MM-DD")

Copy formula, paste as values, save as CSV.

Change Date Format in Text Editor

Method: Find and Replace

  1. Open CSV in text editor
  2. Use regex find/replace:
    • Find: (\d{2})/(\d{2})/(\d{4})
    • Replace: $3-$1-$2
  3. Converts MM/DD/YYYY to YYYY-MM-DD
  4. Save file

Note: Be careful with regex - test on sample first.

Step 4: Change Number Format

Modify how numbers are formatted.

Change Decimal Separator

Comma to Period (European to US):

  1. Open CSV in text editor
  2. Find: , (comma in numbers)
  3. Replace: . (period)
  4. Important: Only replace in number context
  5. Save file

Period to Comma (US to European):

  1. Open CSV in text editor
  2. Find: . (period in numbers)
  3. Replace: , (comma)
  4. Save file

Change Thousands Separator

Add thousands separator:

  1. Open CSV in Excel
  2. Format number column
  3. Apply number format with thousands separator
  4. Save as CSV
  5. Numbers formatted with separators

Step 5: Modify Headers

Change header names and structure.

Rename Headers

Method 1: Excel

  1. Open CSV in Excel
  2. Edit header row directly
  3. Change header names
  4. Save as CSV

Method 2: Text Editor

  1. Open CSV in text editor
  2. Edit first line (header row)
  3. Change header names
  4. Save file

Add Headers

If CSV has no headers:

  1. Open CSV in text editor
  2. Insert new first line
  3. Add header names separated by delimiter
  4. Save file

Remove Headers

If headers not needed:

  1. Open CSV in text editor
  2. Delete first line
  3. Save file

Step 6: Reorder Columns

Rearrange columns in different order.

Reorder in Excel

Method 1: Cut and Paste

  1. Open CSV in Excel
  2. Select column
  3. Cut (Ctrl+X)
  4. Select destination
  5. Insert cut cells
  6. Repeat for all columns
  7. Save as CSV

Method 2: Power Query

  1. Data > From Text/CSV
  2. Select CSV file
  3. Click Transform Data
  4. Reorder columns by dragging
  5. Home > Close & Load
  6. Save as CSV

Step 7: Change Quote Style

Modify how text is quoted in CSV.

Add Quotes Around Text

Method: Text Editor with Regex

  1. Open CSV in text editor
  2. Use regex find/replace:
    • Find: ^([^,]+),
    • Replace: "$1",
  3. Adds quotes around first column
  4. Repeat for other columns
  5. Save file

Note: Complex - may need custom script.

Remove Quotes

Method: Find and Replace

  1. Open CSV in text editor
  2. Find: "
  3. Replace: (blank)
  4. Click Replace All
  5. Quotes removed
  6. Save file

Warning: Only if quotes not needed for data containing delimiters.

Step 8: Change Line Endings

Modify line ending characters.

Convert Windows to Unix (CRLF to LF)

Method 1: Text Editor

  1. Open CSV in text editor (Notepad++, VS Code)
  2. Edit > EOL Conversion > Unix (LF)
  3. Save file
  4. Line endings converted

Method 2: Command Line

dos2unix file.csv

Convert Unix to Windows (LF to CRLF)

Method 1: Text Editor

  1. Open CSV in text editor
  2. Edit > EOL Conversion > Windows (CRLF)
  3. Save file

Method 2: Command Line

unix2dos file.csv

Step 9: Convert Data Types

Change how data is represented.

Convert Text to Numbers

In Excel:

  1. Open CSV in Excel
  2. Select text number column
  3. Data > Text to Columns
  4. Choose General or Number
  5. Click Finish
  6. Numbers converted
  7. Save as CSV

Convert Numbers to Text

In Excel:

  1. Format column as Text
  2. Re-enter values (or use formula)
  3. Save as CSV
  4. Numbers saved as text

Step 10: Restructure CSV Format

Modify overall CSV structure.

Add Columns

Method: Excel

  1. Open CSV in Excel
  2. Insert new column
  3. Add data or formulas
  4. Save as CSV

Remove Columns

Method: Excel

  1. Open CSV in Excel
  2. Select column
  3. Right-click > Delete
  4. Column removed
  5. Save as CSV

Combine Columns

Method: Excel Formula

=A2&" "&B2

Combines two columns with space. Copy, paste as values, save as CSV.

Real Example: Changing CSV Formatting

Before (Original Format):

Name,Price,Date
Laptop,999.99,11/25/2025
Monitor,299.99,11/25/2025

Format:

  • Comma delimiter
  • US date format
  • Period decimal separator

After (Changed Format):

Name;Price;Date
Laptop;999,99;2025-11-25
Monitor;299,99;2025-11-25

Changes applied:

  1. Delimiter: Comma → Semicolon
  2. Date format: MM/DD/YYYY → YYYY-MM-DD
  3. Decimal: Period → Comma (European format)

Formatting Change Checklist

Use this checklist when changing CSV formatting:

  • Identified required format changes
  • Changed delimiter (if needed)
  • Converted encoding (if needed)
  • Modified date format (if needed)
  • Changed number format (if needed)
  • Updated headers (if needed)
  • Reordered columns (if needed)
  • Modified quote style (if needed)
  • Changed line endings (if needed)
  • Converted data types (if needed)
  • Restructured format (if needed)
  • Tested new format
  • Verified compatibility

Mini Automation Using RowTidy

You can change CSV formatting automatically using RowTidy's intelligent format conversion.

The Problem:
Changing CSV formatting manually is time-consuming:

  • Modifying delimiters
  • Converting encoding
  • Changing date/number formats
  • Restructuring data

The Solution:
RowTidy changes CSV formatting automatically:

  1. Upload CSV file - Drag and drop
  2. Specify target format - Choose delimiter, encoding, formats
  3. AI transforms format - Applies all format changes
  4. Downloads formatted CSV - Get file in desired format

RowTidy Features:

  • Delimiter conversion - Comma, semicolon, tab, custom
  • Encoding conversion - UTF-8, Windows-1252, ASCII
  • Date format conversion - Any format to any format
  • Number format conversion - Decimal separators, thousands separators
  • Structure modification - Column reordering, header changes
  • Format validation - Ensures format is correct

Time saved: 1 hour manual formatting → 3 minutes automated

Instead of manually changing CSV formatting, let RowTidy automate the process. Try RowTidy's format conversion →

FAQ

1. How do I change CSV delimiter from comma to semicolon?

Use Excel Save As (CSV Semicolon delimited), or use Find & Replace in text editor (carefully), or use Power Query. RowTidy converts delimiters automatically.

2. How do I change CSV encoding to UTF-8?

Open in text editor, Save As with UTF-8 encoding, or use Excel Import/Export with UTF-8. RowTidy converts encoding automatically.

3. Can I change date format in CSV?

Yes. Use Excel Text to Columns to convert dates, then format and save. Or use text editor with regex (advanced). RowTidy converts date formats automatically.

4. How do I change number format in CSV?

Modify decimal separator using Find & Replace in text editor, or format in Excel then save. RowTidy converts number formats automatically.

5. How do I reorder columns in CSV?

Use Excel to cut/paste columns, or use Power Query to reorder, then save as CSV. RowTidy can reorder columns automatically.

6. Can I change CSV quote style?

Yes, but complex. Use text editor with regex (advanced) or custom script. RowTidy handles quote styles automatically.

7. How do I convert line endings in CSV?

Use text editor (Notepad++, VS Code) to convert EOL (CRLF/LF), or use command line tools (dos2unix/unix2dos). RowTidy handles line endings.

8. Should I change CSV format before importing?

Depends on target system. Some systems require specific formats (delimiter, encoding). Check requirements first. RowTidy helps convert to required format.

9. Can RowTidy change CSV formatting automatically?

Yes. RowTidy converts delimiters, encoding, date/number formats, and structure automatically based on your requirements.

10. What's the safest way to change CSV formatting?

Use Excel for data transformations, text editor for simple changes, or automated tools like RowTidy for complex conversions. Always backup original file first.

Related Guides

Conclusion

Changing CSV formatting requires modifying delimiters, encoding, data formats, and structure to meet specific requirements. Use Excel, text editors, or automated tools like RowTidy to convert formats efficiently and accurately.

Try RowTidy — automatically change CSV formatting to meet your specific requirements and system compatibility needs.