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How to Open CSV File Correctly: Import Methods Guide

Learn how to open CSV files correctly in Excel and other tools. Discover proper import methods, encoding settings, and delimiter selection to avoid data corruption.

RowTidy Team
Nov 22, 2025
11 min read
CSV, Excel, File Import, Data Import, Best Practices

How to Open CSV File Correctly: Import Methods Guide

If you're opening CSV files by double-clicking, you're likely corrupting your data. 68% of Excel users open CSV files incorrectly, causing encoding issues, wrong data types, and formatting problems.

By the end of this guide, you'll know how to open CSV files correctly—using proper import methods, selecting right settings, and preserving data integrity.

Quick Summary

  • Use Import Wizard - Don't double-click, use Data > From Text/CSV
  • Select correct encoding - Choose UTF-8 or detect automatically
  • Choose right delimiter - Comma, semicolon, or tab
  • Set data types - Specify types during import to avoid errors

Common Problems from Incorrect CSV Opening

  1. Encoding corruption - Wrong encoding shows garbled characters
  2. Data type errors - Numbers become text, dates become text
  3. Delimiter issues - Wrong delimiter puts data in wrong columns
  4. Format loss - Leading zeros removed, dates reformatted
  5. Quote problems - Quotes not handled correctly
  6. Large file issues - Excel truncates large CSV files
  7. Special character loss - Line breaks, tabs lost
  8. Header issues - Headers not recognized correctly
  9. Decimal separator - Commas vs periods causing number errors
  10. Date format confusion - Dates interpreted incorrectly

Step-by-Step: How to Open CSV Files Correctly

Method 1: Excel Import Wizard (Recommended)

The import wizard gives you control over how CSV is opened.

Steps

  1. Open Excel

    • Don't double-click CSV file
    • Open Excel first

  2. Start Import

    • Go to Data > From Text/CSV
    • Or Data > Get Data > From File > From Text/CSV

  3. Select CSV File

    • Browse to CSV file
    • Select file
    • Click Import

  4. Preview and Adjust

    • Preview shows how data will import
    • Adjust settings if needed:
      • File Origin (Encoding): Choose UTF-8
      • Delimiter: Select comma, semicolon, or tab
      • Data Type Detection: Automatic or manual

  5. Transform Data (Optional)

    • Click Transform Data for Power Query
    • Or click Load to import directly

  6. Load Data

    • Click Load
    • Data imports with correct settings

Method 2: Specify Encoding

Choose correct encoding to avoid character corruption.

Detect Encoding

Common encodings:

  • UTF-8 - Standard, handles all characters
  • Windows-1252 - Western European
  • ISO-8859-1 - Latin-1
  • ASCII - Basic characters only

Select Encoding in Import

In Excel Import Wizard:

  1. Click File Origin dropdown
  2. Try different encodings:
    • UTF-8 (most common)
    • Windows-1252
    • ISO-8859-1
  3. Preview updates to show result
  4. Choose encoding that shows correct characters

Or let Excel detect:

  • Excel auto-detects encoding
  • Usually works correctly
  • Verify in preview

Method 3: Choose Correct Delimiter

Select right delimiter to align columns correctly.

Identify Delimiter

Common delimiters:

  • Comma (,) - Most common, standard CSV
  • Semicolon (;) - European CSV
  • Tab - TSV (Tab-Separated Values)
  • Pipe (|) - Less common

Select Delimiter in Import

In Excel Import Wizard:

  1. Click Delimiter dropdown
  2. Try different delimiters:
    • Comma
    • Semicolon
    • Tab
    • Custom
  3. Preview updates to show column structure
  4. Choose delimiter that aligns columns correctly

Or let Excel detect:

  • Excel auto-detects delimiter
  • Usually identifies correctly
  • Verify in preview

Method 4: Set Data Types

Specify data types during import to avoid errors.

Preview Data Types

In Import Wizard:

  1. Preview shows detected data types
  2. Click column headers to change type:
    • General - Excel decides
    • Text - Keep as text
    • Date - Interpret as date
    • Number - Interpret as number
    • Do not import - Skip column

Set Types Correctly

For each column:

  • Names/Text: Set to Text (preserves leading zeros, special chars)
  • Numbers: Set to Number (enables calculations)
  • Dates: Set to Date (enables date functions)
  • IDs: Set to Text (preserves format)

Example:

  • Product Code: Text (preserves leading zeros)
  • Price: Number (enables calculations)
  • Date: Date (enables date functions)
  • Description: Text (preserves formatting)

Method 5: Handle Headers

Ensure headers are recognized correctly.

Check Header Row

In Import Wizard:

  1. Preview shows first row
  2. Check if first row contains headers
  3. Excel usually detects headers automatically

Set Header Row

If headers in different row:

  1. Use Power Query (Transform Data)
  2. Home > Use First Row as Headers
  3. Or promote specific row as headers
  4. Load data

Method 6: Handle Large Files

Large CSV files need special handling.

Excel Row Limit

Excel limits:

  • Excel 2007+: 1,048,576 rows
  • Older versions: 65,536 rows

If file exceeds limit:

  • Use Power Query (handles larger files)
  • Or split file into smaller chunks
  • Or use specialized tools

Use Power Query for Large Files

Steps:

  1. Data > From Text/CSV
  2. Select large CSV file
  3. Click Transform Data (Power Query)
  4. Power Query handles large files better
  5. Load to data model or worksheet

Method 7: Preserve Formatting

Maintain data format during import.

Preserve Leading Zeros

For IDs, codes:

  1. Set column to Text during import
  2. Prevents Excel from removing leading zeros
  3. Example: "00123" stays as "00123", not 123

Preserve Special Characters

For text with special chars:

  1. Set column to Text
  2. Preserves line breaks, tabs, quotes
  3. Or handle in Power Query

Method 8: Fix Common Import Issues

Address issues that occur during import.

Fix Date Format Issues

Problem: Dates imported as text or wrong format

Solution:

  1. Set column to Date during import
  2. Choose date format (MDY, DMY, YMD)
  3. Or fix after import using DATEVALUE()

Fix Number Format Issues

Problem: Numbers imported as text

Solution:

  1. Set column to Number during import
  2. Or convert after import using VALUE()
  3. Remove currency symbols, commas first

Fix Decimal Separator Issues

Problem: European format (comma as decimal) vs US (period)

Solution:

  1. Use Power Query to handle
  2. Replace comma with period before import
  3. Or set regional settings

Real Example: Opening CSV Correctly

Incorrect Method (Double-Click):

Result:

  • Encoding: Windows-1252 (wrong)
  • Delimiters: Auto-detected (may be wrong)
  • Data types: Excel decides (often wrong)
  • Leading zeros: Removed
  • Dates: May be wrong format

Problems:

  • Garbled characters
  • Numbers as text
  • Dates as text
  • Format lost

Correct Method (Import Wizard):

Steps:

  1. Data > From Text/CSV
  2. Select file
  3. Encoding: UTF-8
  4. Delimiter: Comma
  5. Data types: Set manually
  6. Load

Result:

  • Correct encoding
  • Proper column alignment
  • Correct data types
  • Format preserved

Best Practices for Opening CSV

1. Always Use Import Wizard

Never double-click:

  • Double-clicking uses default settings
  • Often wrong encoding, delimiter, data types
  • Import wizard gives control

2. Check Preview Before Loading

Always preview:

  • Verify encoding is correct
  • Check delimiter aligns columns
  • Confirm data types are right
  • Adjust before loading

3. Set Data Types Explicitly

Don't rely on auto-detection:

  • Set types manually for accuracy
  • Prevents format loss
  • Ensures correct interpretation

4. Use Power Query for Complex Files

For advanced needs:

  • Power Query offers more control
  • Better for large files
  • More transformation options

5. Save Import Settings

For repeated imports:

  • Create Power Query query
  • Save import settings
  • Reuse for similar files

Mini Automation Using RowTidy

You can ensure CSV files open correctly by cleaning them first with RowTidy.

The Problem:
Opening CSV files incorrectly causes:

  • Encoding corruption
  • Wrong data types
  • Format loss
  • Import errors

The Solution:
RowTidy prepares CSV files for correct opening:

  1. Upload CSV file - Drag and drop
  2. AI fixes format issues - Standardizes encoding, delimiters, structure
  3. Downloads clean CSV - Get file ready for import
  4. Opens correctly - File imports without issues

RowTidy Features:

  • Encoding standardization - Converts to UTF-8
  • Delimiter standardization - Ensures consistent delimiters
  • Structure validation - Fixes quotes, line breaks
  • Format cleaning - Prepares data for correct import
  • Import-ready files - CSV files that open correctly

Time saved: Avoid import errors and data corruption

Clean your CSV files with RowTidy before opening to ensure correct import. Try RowTidy's CSV cleaning →

FAQ

1. Why shouldn't I double-click CSV files?

Double-clicking uses default Excel settings (often wrong encoding, delimiter, data types), causing corruption. Use Import Wizard for control.

2. What encoding should I use for CSV files?

UTF-8 is standard and handles all characters. Use UTF-8 unless file specifically requires different encoding. RowTidy ensures UTF-8 encoding.

3. How do I know which delimiter to use?

Check CSV file in text editor: comma (,) is most common, semicolon (;) for European, tab for TSV. Excel Import Wizard auto-detects, verify in preview.

4. Should I set data types during import?

Yes. Setting types explicitly prevents errors: Text for IDs/codes (preserves format), Number for calculations, Date for date functions. Auto-detection often wrong.

5. How do I preserve leading zeros in CSV?

Set column to Text during import. If already imported, format as Text and re-enter values, or import again with Text type. RowTidy preserves formats.

6. What if my CSV file is too large for Excel?

Use Power Query (handles larger files), split file into chunks, or use specialized tools. Power Query can load to data model (no row limit).

7. How do I fix dates imported incorrectly?

Set column to Date during import and choose format. Or fix after import using DATEVALUE() or Text to Columns with Date format. RowTidy standardizes dates.

8. Can I save import settings for reuse?

Yes. Create Power Query query with your import settings, save query, reuse for similar files. Saves time on repeated imports.

9. What's the difference between Load and Transform Data?

Load imports directly to worksheet. Transform Data opens Power Query for advanced transformations before loading. Use Transform for complex needs.

10. How do I open CSV correctly on Mac?

Same process: Use Data > From Text/CSV (or Get External Data > From Text), select encoding, delimiter, data types. Mac Excel has same import wizard.

Related Guides

Conclusion

Opening CSV files correctly requires using Import Wizard instead of double-clicking, selecting correct encoding (UTF-8), choosing right delimiter, setting data types explicitly, and checking preview before loading. Proper import methods prevent data corruption and ensure accurate data. Clean CSV files with tools like RowTidy before opening for best results.

Try RowTidy — clean CSV files before opening to ensure they import correctly every time.