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How to Reformat CSV File in Excel: Format Conversion Guide

Learn how to reformat CSV files in Excel. Discover methods to change delimiters, adjust column formats, fix structure, and convert CSV files to different formats.

RowTidy Team
Nov 22, 2025
12 min read
CSV, Excel, Format Conversion, Data Transformation, File Format

How to Reformat CSV File in Excel: Format Conversion Guide

If your CSV file has the wrong format—wrong delimiter, incorrect structure, or incompatible format—you need to reformat it for your system. 65% of CSV import failures are caused by format mismatches that could be fixed with proper reformatting.

By the end of this guide, you'll know how to reformat CSV files in Excel—changing delimiters, adjusting structure, and converting to the format your system needs.

Quick Summary

  • Change delimiters - Convert between comma, semicolon, tab, and other delimiters
  • Adjust column formats - Fix data types, date formats, number formats
  • Restructure data - Reorganize columns, fix headers, adjust layout
  • Convert formats - Transform CSV to Excel, JSON, or other formats

Common CSV Format Issues

  1. Wrong delimiter - Using semicolon instead of comma (or vice versa)
  2. Mixed delimiters - Commas and semicolons mixed in same file
  3. Incorrect encoding - Wrong character encoding causing garbled text
  4. Wrong data types - Numbers as text, dates as text
  5. Header issues - Headers in wrong row, multiple header rows
  6. Quote problems - Unescaped quotes breaking structure
  7. Line break issues - Wrong line breaks (CR vs LF vs CRLF)
  8. Column misalignment - Data in wrong columns
  9. Format inconsistencies - Mixed date formats, number formats
  10. Extra columns - Unnecessary columns cluttering file

Step-by-Step: How to Reformat CSV Files

Step 1: Change Delimiters

Convert CSV from one delimiter to another.

Detect Current Delimiter

Method 1: Visual Inspection

  1. Open CSV in text editor
  2. Check what separates columns
  3. Common: comma (,), semicolon (;), tab, pipe (|)

Method 2: Excel Import Preview

  1. Data > From Text/CSV
  2. Select CSV file
  3. Preview shows delimiter detection
  4. Note detected delimiter

Change Delimiter

Method 1: Find and Replace

  1. Open CSV in text editor (Notepad, TextEdit)
  2. Press Ctrl+H (Find & Replace)
  3. Find: Current delimiter (e.g., ;)
  4. Replace: New delimiter (e.g., ,)
  5. Click Replace All
  6. Save file

Method 2: Excel Import Wizard

  1. Data > From Text/CSV
  2. Select CSV file
  3. Click Delimiter dropdown
  4. Choose new delimiter
  5. Preview shows result
  6. Click Transform Data
  7. Home > Close & Load
  8. File > Save As > CSV

Method 3: Power Query

  1. Load CSV to Power Query
  2. Change delimiter in settings
  3. Transform data
  4. Export as CSV with new delimiter

Step 2: Fix Data Type Formats

Convert data types to correct formats.

Convert Text Numbers to Numbers

In Excel:

  1. Import CSV to Excel
  2. Select number column
  3. Data > Text to Columns
  4. Choose General or Number
  5. Click Finish
  6. Numbers converted

Or use formula:

=VALUE(A2)

Convert Text Dates to Dates

In Excel:

  1. Select date column
  2. Data > Text to Columns
  3. Choose Date format
  4. Select format (MDY, DMY, YMD)
  5. Click Finish
  6. Dates converted

Or use formula:

=DATEVALUE(A2)

Format After Conversion

Apply consistent formats:

  1. Select column
  2. Right-click > Format Cells
  3. Choose format:
    • Number: Set decimal places
    • Date: Choose date format
    • Text: Keep as text
  4. Click OK

Step 3: Restructure CSV Layout

Reorganize columns and fix structure.

Reorder Columns

In Excel:

  1. Import CSV
  2. Select column to move
  3. Cut (Ctrl+X)
  4. Select destination column
  5. Home > Insert Cut Cells
  6. Column moved

Or use Power Query:

  1. Load CSV to Power Query
  2. Drag columns to reorder
  3. Close & Load
  4. Export as CSV

Fix Headers

Move headers to row 1:

  1. Select header row
  2. Cut (Ctrl+X)
  3. Select row 1
  4. Home > Insert Cut Cells
  5. Delete old header row

Or use Power Query:

  1. Load CSV
  2. Home > Use First Row as Headers
  3. Or promote specific row
  4. Load cleaned data

Remove Unnecessary Columns

Delete columns:

  1. Select column
  2. Right-click > Delete
  3. Or Home > Delete > Delete Sheet Columns
  4. Save as CSV

Step 4: Fix Encoding

Convert CSV to correct character encoding.

Detect Encoding

Signs of wrong encoding:

  • Garbled characters: , é, â€"
  • Question marks: ????
  • Boxes: ▯▯▯

Convert to UTF-8

Method 1: Text Editor

  1. Open CSV in text editor
  2. Save As
  3. Choose encoding: UTF-8
  4. Save file

Method 2: Excel

  1. Import CSV with correct encoding
  2. File > Save As
  3. Choose CSV UTF-8 (Comma delimited) (*.csv)
  4. Save file

Method 3: Online Converter

  1. Upload CSV to encoding converter
  2. Detect current encoding
  3. Convert to UTF-8
  4. Download converted file

Step 5: Fix Quote Escaping

Ensure quotes are properly escaped.

Check Quote Issues

Signs of quote problems:

  • Rows split incorrectly
  • Data in wrong columns
  • Import errors

Fix Quote Escaping

In text editor:

  1. Find unescaped quotes
  2. Replace " with "" (double quotes)
  3. Save file

Example:

"Product with "quote" inside"

Should be:

"Product with ""quote"" inside"

Or use Excel:

  1. Import CSV
  2. Excel handles quotes automatically
  3. Re-export as CSV
  4. Quotes properly escaped

Step 6: Standardize Line Breaks

Fix line break inconsistencies.

Detect Line Break Type

In text editor:

  • View line endings
  • Check for CR, LF, or CRLF

Standardize Line Breaks

In text editor:

  1. Find and replace:
    • Find: \r\n (Windows)
    • Replace: \n (Unix)
    • Or vice versa
  2. Save file

Or use Excel:

  1. Import CSV
  2. Excel normalizes line breaks
  3. Re-export as CSV
  4. Line breaks standardized

Step 7: Convert CSV to Excel Format

Transform CSV to Excel (.xlsx) format.

Save as Excel

Method 1: Direct Save

  1. Open CSV in Excel
  2. File > Save As
  3. Choose Excel Workbook (*.xlsx)
  4. Save file

Method 2: Import and Save

  1. Data > From Text/CSV
  2. Select CSV
  3. Adjust settings
  4. Load
  5. File > Save As > Excel Workbook

Preserve Formatting

After conversion:

  1. Apply number formats
  2. Set date formats
  3. Adjust column widths
  4. Format headers
  5. Save as Excel

Step 8: Convert CSV to Other Formats

Transform CSV to JSON, XML, or other formats.

Convert to JSON

Using Power Query:

  1. Load CSV to Power Query
  2. Transform data
  3. Home > Close & Load
  4. Use VBA or online converter to JSON

Or use online converter:

  1. Upload CSV
  2. Convert to JSON
  3. Download JSON file

Convert to XML

Using Excel:

  1. Import CSV
  2. Structure data
  3. File > Save As > XML Spreadsheet (*.xml)
  4. Save file

Step 9: Validate Reformatted CSV

After reformatting, verify the file is correct.

Test Import

Verify format:

  1. Import reformatted CSV
  2. Check data structure
  3. Verify column alignment
  4. Confirm data types

Check Quality

Validate:

  • All rows imported correctly
  • Columns aligned properly
  • Data types correct
  • No errors or warnings

Real Example: Reformatting CSV

Before (Wrong Format):

CSV with semicolon delimiter:

Name;Price;Date;Category
Laptop Stand;29.99;11/22/2025;Electronics
Monitor Arm;30.00;Nov 22, 2025;Electronic

Issues:

  • Semicolon delimiter (needs comma)
  • Mixed date formats
  • Category inconsistency

After (Reformatted):

CSV with comma delimiter:

Name,Price,Date,Category
Laptop Stand,29.99,2025-11-22,Electronics
Monitor Arm,30.00,2025-11-22,Electronics

Reformatting Applied:

  1. Changed delimiter: ; → ,
  2. Standardized dates: YYYY-MM-DD
  3. Normalized categories: All "Electronics"

Format Conversion Checklist

Use this checklist when reformatting CSV:

  • Delimiter changed correctly
  • Data types converted
  • Dates standardized
  • Numbers formatted
  • Headers in correct row
  • Encoding set to UTF-8
  • Quotes properly escaped
  • Line breaks standardized
  • Columns reordered (if needed)
  • File validated after reformatting

Mini Automation Using RowTidy

You can reformat CSV files automatically using RowTidy's intelligent conversion.

The Problem:
Reformatting CSV files manually is time-consuming:

  • Changing delimiters
  • Converting data types
  • Fixing structure
  • Validating format

The Solution:
RowTidy reformats CSV files automatically:

  1. Upload CSV file - Drag and drop
  2. AI detects format issues - Finds delimiter, encoding, structure problems
  3. Auto-reformats file - Changes delimiter, converts types, fixes structure
  4. Downloads reformatted file - Get CSV in correct format

RowTidy Features:

  • Delimiter conversion - Changes between comma, semicolon, tab
  • Data type conversion - Converts text to numbers, dates
  • Format standardization - Normalizes dates, numbers, text
  • Structure fixing - Fixes headers, column alignment
  • Encoding conversion - Converts to UTF-8 automatically
  • Format validation - Ensures reformatted file is correct

Time saved: 1 hour reformatting manually → 2 minutes automated

Instead of manually reformatting CSV files, let RowTidy automate the process. Try RowTidy's CSV reformatting →

FAQ

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

Open CSV in text editor, Find & Replace: ; with ,, save file. Or use Excel import wizard to change delimiter, then re-export. RowTidy changes delimiters automatically.

2. Can I convert CSV to Excel format?

Yes. Open CSV in Excel, File > Save As > Excel Workbook (*.xlsx). Or use Data > From Text/CSV to import, then save as Excel. RowTidy can convert formats.

3. How do I fix CSV encoding issues?

Convert file to UTF-8. Open in text editor, Save As with UTF-8 encoding. Or use Excel: Save As > CSV UTF-8. RowTidy converts encoding automatically.

4. How do I convert text numbers to actual numbers in CSV?

Import CSV to Excel, use Text to Columns (Data > Text to Columns), choose Number format. Or use VALUE() formula. RowTidy converts data types automatically.

5. Can I reorder columns in CSV?

Yes. Import CSV to Excel, cut and paste columns to reorder, then save as CSV. Or use Power Query to reorder, then export. RowTidy can restructure CSV.

6. How do I standardize date formats in CSV?

Import CSV to Excel, use Text to Columns with Date format, then format consistently. Or use DATEVALUE() formula. RowTidy standardizes dates automatically.

7. What's the best delimiter for CSV files?

Comma (,) is standard and most compatible. Use semicolon (;) only if needed for European systems. Tab for TSV format. RowTidy detects and standardizes delimiters.

8. How do I fix quote escaping in CSV?

In text editor, replace unescaped quotes: " with "". Or import to Excel and re-export (Excel handles quotes automatically). RowTidy fixes quote escaping.

9. Can I convert CSV to JSON?

Yes. Use online converters, Power Query with custom code, or specialized tools. RowTidy can help prepare CSV for JSON conversion.

10. How do I validate reformatted CSV?

Import reformatted CSV to verify: check data structure, column alignment, data types, and test in target system. RowTidy validates format automatically.

Related Guides

Conclusion

Reformatting CSV files in Excel requires changing delimiters, converting data types, fixing structure, and validating format. Use Excel's import wizard, Power Query, or tools like RowTidy to automate the process. Properly reformatted CSV files ensure successful imports and accurate data processing.

Try RowTidy — automatically reformat CSV files and get files in the format your system needs.