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What is Wrong with My CSV File: Diagnostic Guide

Learn how to diagnose what's wrong with your CSV file. Discover common issues, diagnostic methods, and solutions to identify and fix CSV file problems.

RowTidy Team
Nov 22, 2025
12 min read
CSV, Troubleshooting, Diagnostics, File Issues, Error Detection

What is Wrong with My CSV File: Diagnostic Guide

If your CSV file isn't working—won't import, shows errors, or displays incorrectly—you need diagnostic methods to identify the problem. 69% of CSV issues go unresolved because users don't know how to diagnose the problem.

By the end of this guide, you'll know how to diagnose what's wrong with your CSV file—using systematic methods to identify issues and apply the right fixes.

Quick Summary

  • Systematic diagnosis - Check structure, encoding, delimiters, and data
  • Common issues - Encoding problems, delimiter issues, quote errors, format problems
  • Diagnostic tools - Use text editors, Excel, validators to identify issues
  • Fix methods - Apply appropriate solutions based on diagnosis

Common CSV File Problems

  1. Won't open - File appears corrupted or unreadable
  2. Import errors - Excel/other tools can't import file
  3. Weird characters - Garbled text, question marks, boxes
  4. Wrong columns - Data in wrong columns after import
  5. Missing rows - Fewer rows imported than file has
  6. Extra columns - More columns than expected
  7. Broken structure - Rows split incorrectly
  8. Encoding issues - Character display problems
  9. Delimiter problems - Wrong delimiter causing misalignment
  10. Quote errors - Unescaped quotes breaking structure

Step-by-Step: Diagnose CSV File Issues

Step 1: Check File Can Be Opened

First, verify the file is readable.

Try Opening in Text Editor

Test basic readability:

  1. Open CSV in Notepad, TextEdit, or VS Code
  2. Check if file opens
  3. Check if content is visible
  4. Look for obvious corruption

If file won't open:

  • File may be corrupted
  • Wrong file format
  • File is binary, not text
  • Need to recover file

Check File Size

Verify file size:

  • Compare to expected size
  • Very small = truncated file
  • Very large = may have binary data
  • Zero bytes = empty file

Check File Extension

Verify extension:

  • Should be .csv
  • If .txt, rename to .csv
  • If other extension, may be wrong format

Step 2: Check Encoding

Encoding issues cause character display problems.

Identify Encoding Issues

Signs:

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

Test Different Encodings

In text editor:

  1. Try opening with different encoding
  2. UTF-8
  3. Windows-1252
  4. ISO-8859-1
  5. See which displays correctly

In Excel:

  1. Data > From Text/CSV
  2. Try different encodings from dropdown
  3. Preview shows result
  4. Identify correct encoding

Step 3: Check Delimiters

Delimiter issues cause column misalignment.

Identify Delimiter

Visual inspection:

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

Excel import preview:

  1. Data > From Text/CSV
  2. Preview shows detected delimiter
  3. Check if correct
  4. Try different delimiters

Check for Mixed Delimiters

Look for:

  • Some rows use comma
  • Other rows use semicolon
  • Inconsistent delimiters
  • Causes column misalignment

Step 4: Check Quote Escaping

Quote issues break row structure.

Identify Quote Problems

Signs:

  • Rows split incorrectly
  • Data in wrong rows
  • Import shows fewer rows
  • Error messages about quotes

Check for:

  • Unescaped quotes within cells
  • Unclosed quotes
  • Wrong quote style

Test Quote Handling

In text editor:

  • Look for quote patterns
  • Check if quotes are escaped
  • Verify quote consistency

In Excel import:

  • Set text qualifier to "
  • Preview shows quote handling
  • Adjust if needed

Step 5: Check Line Breaks

Line break issues cause row problems.

Identify Line Break Type

Common types:

  • CRLF (\r\n) - Windows
  • LF (\n) - Unix/Linux/Mac
  • CR (\r) - Old Mac

Check in text editor:

  • View line endings
  • Identify type
  • Check for consistency

Test Line Breaks

If rows merged:

  • Wrong line breaks
  • Need to standardize
  • Convert to consistent type

Step 6: Check Data Structure

Verify CSV structure is correct.

Check Headers

Verify:

  • Headers in first row
  • No duplicate headers
  • Headers match data
  • Headers properly formatted

Check Row Count

Compare:

  • Expected row count
  • Actual row count after import
  • If different, structure issue

Check Column Count

Verify:

  • Expected columns
  • Actual columns after import
  • If different, delimiter or structure issue

Step 7: Check Data Quality

Verify data itself is correct.

Check for Missing Data

Identify:

  • Blank cells
  • NULL values
  • Incomplete rows
  • Missing critical fields

Check Data Types

Verify:

  • Numbers are numbers
  • Dates are dates
  • Text is text
  • Types match expectations

Check for Invalid Values

Identify:

  • Outliers
  • Impossible values
  • Wrong formats
  • Invalid entries

Step 8: Use CSV Validator

Use tools to validate CSV structure.

Online CSV Validators

Use validators to:

  • Check CSV syntax
  • Identify structural errors
  • Validate encoding
  • Check delimiter consistency

Excel Import Wizard

Use as validator:

  1. Data > From Text/CSV
  2. Preview shows issues
  3. Identifies problems
  4. Shows what's wrong

Step 9: Compare with Working CSV

Compare problematic file with working example.

Find Working Example

Get reference:

  • Similar CSV that works
  • Template CSV
  • Example from documentation

Compare Structure

Check differences:

  • Delimiter
  • Encoding
  • Quote style
  • Line breaks
  • Headers
  • Structure

Identify Differences

Note what's different:

  • These are likely the problems
  • Fix to match working example
  • Test after fixing

Step 10: Document Issues

Record what's wrong for fixing.

Create Issue List

Document:

Issue Location Severity Fix Method
Encoding Entire file High Convert to UTF-8
Delimiter Row 5, 10 Medium Standardize delimiter
Quote Row 15 High Escape quotes

Prioritize Fixes

Fix order:

  1. Critical issues first (structure, encoding)
  2. High severity (quote errors, delimiter issues)
  3. Medium severity (format issues)
  4. Low severity (minor inconsistencies)

Real Example: Diagnosing CSV Issues

Symptoms:

File won't import correctly:

  • Shows error: "Unterminated quoted field"
  • Only 50 rows imported (file has 100)
  • Data in wrong columns

Diagnosis Process:

Step 1: Opened in text editor

  • File opens, content visible
  • Not corrupted

Step 2: Checked encoding

  • Tried UTF-8: weird characters
  • Tried Windows-1252: displays correctly
  • Encoding issue identified

Step 3: Checked delimiters

  • Most rows use comma
  • Some rows use semicolon
  • Mixed delimiter issue

Step 4: Checked quotes

  • Row 15 has unescaped quote
  • Breaks structure
  • Quote issue identified

Issues Found:

  1. Wrong encoding (Windows-1252, needs UTF-8)
  2. Mixed delimiters (comma and semicolon)
  3. Unescaped quote in row 15

Fixes Applied:

  1. Converted to UTF-8
  2. Standardized to comma delimiter
  3. Escaped quote properly

Result: File imports correctly

Diagnostic Checklist

Use this checklist to diagnose CSV issues:

  • File opens in text editor
  • File size is reasonable
  • Encoding is correct (UTF-8)
  • Delimiter is consistent
  • Quotes are properly escaped
  • Line breaks are consistent
  • Headers are correct
  • Row count matches expected
  • Column count matches expected
  • Data types are correct

Mini Automation Using RowTidy

You can diagnose and fix CSV file issues automatically using RowTidy's intelligent diagnostics.

The Problem:
Diagnosing CSV issues manually is time-consuming:

  • Checking encoding, delimiters, quotes
  • Testing different settings
  • Identifying root causes
  • Applying fixes

The Solution:
RowTidy diagnoses and fixes CSV issues automatically:

  1. Upload CSV file - Drag and drop
  2. AI diagnoses issues - Identifies encoding, delimiter, quote, structure problems
  3. Shows diagnostic report - Lists all issues found
  4. Auto-fixes problems - Applies fixes automatically
  5. Downloads fixed file - Get working CSV

RowTidy Diagnostic Features:

  • Encoding detection - Identifies encoding issues automatically
  • Delimiter analysis - Detects delimiter problems
  • Quote validation - Finds quote escaping issues
  • Structure checking - Identifies structural problems
  • Data quality analysis - Checks data types and validity
  • Comprehensive report - Shows all issues and fixes

Time saved: 2 hours diagnosing manually → 2 minutes automated

Instead of manually diagnosing CSV issues, let RowTidy identify and fix problems automatically. Try RowTidy's CSV diagnostics →

FAQ

1. How do I know what's wrong with my CSV file?

Systematic diagnosis: check if file opens, verify encoding, check delimiters, validate quotes, test line breaks, verify structure, check data quality. RowTidy diagnoses automatically.

2. Why won't my CSV file open?

File may be corrupted, wrong format, binary data, or encoding issue. Try opening in text editor first. RowTidy can help recover corrupted files.

3. How do I check CSV encoding?

Open in text editor, try different encodings (UTF-8, Windows-1252), see which displays correctly. Or use Excel import wizard to test encodings. RowTidy detects encoding automatically.

4. How do I identify delimiter issues?

Open CSV in text editor, check what separates columns. Or use Excel import preview to see detected delimiter. If columns misaligned, delimiter is wrong. RowTidy detects delimiter issues.

5. What if my CSV has quote errors?

Check for unescaped quotes, unclosed quotes, wrong quote style. Use CSV validator or Excel import preview to identify. RowTidy fixes quote errors automatically.

6. How do I validate CSV structure?

Use online CSV validators, Excel import wizard (shows issues in preview), or compare with working CSV. RowTidy validates structure automatically.

7. Can I diagnose CSV issues automatically?

Yes. Use CSV validators, Excel import wizard, or RowTidy which diagnoses all common CSV issues automatically and provides detailed reports.

8. What's the most common CSV problem?

Encoding issues (weird characters) and delimiter problems (wrong columns) are most common. Both easily fixed with proper diagnosis. RowTidy fixes both automatically.

9. How do I fix multiple CSV issues at once?

Use RowTidy which diagnoses all issues and fixes them automatically in one pass. Much faster than fixing issues one by one.

10. Can RowTidy diagnose all CSV problems?

RowTidy diagnoses most common CSV issues: encoding, delimiters, quotes, structure, data quality. For severe corruption, may need specialized recovery tools first.

Related Guides

Conclusion

Diagnosing what's wrong with CSV files requires systematic approach: check file readability, verify encoding, test delimiters, validate quotes, check line breaks, verify structure, and test data quality. Use text editors, Excel import wizard, validators, or tools like RowTidy to automatically diagnose and fix issues. Proper diagnosis ensures you apply the right fix.

Try RowTidy — automatically diagnose and fix CSV file issues and get working files quickly.