CSV Duplicate Remover FAQ

What is CSV deduplication?

CSV deduplication is the process of identifying and removing duplicate rows from CSV (Comma-Separated Values) files. Our tool analyzes your data and removes identical or nearly identical records, helping you clean and organize your data efficiently.

How does the deduplication algorithm work?

Our algorithm works by:

• Parsing your CSV file and reading all rows
• Comparing rows based on the columns you specify (or all columns by default)
• Identifying exact matches or case-insensitive matches (based on your settings)
• Keeping the first or last occurrence of duplicates (your choice)
• Generating a clean CSV file with duplicates removed

Is this service free?

Yes, our CSV deduplication tool is completely free to use. There are no hidden fees, subscriptions, or usage limits for standard file processing.

What file formats are supported?

We support:

• CSV files (.csv) - Standard comma-separated values
• Text files (.txt) - Tab-separated or other delimited text files
• Files with custom delimiters (comma, semicolon, tab, etc.)

What's the maximum file size?

You can upload files up to 100MB in size. For most CSV files, this supports hundreds of thousands to millions of rows, depending on the number of columns and data complexity.

My CSV has special characters or encoding issues. Will it work?

Our tool handles most common text encodings including UTF-8, which supports special characters, accents, and international text. If you encounter issues, try saving your CSV in UTF-8 encoding before uploading.

Can I process Excel files (.xlsx)?

Currently, we only support CSV and text files. To process Excel files, please export them as CSV format first using Excel, Google Sheets, or similar spreadsheet software.

What's the difference between case sensitive and case insensitive matching?

What does "Keep first occurrence" vs "Keep last occurrence" mean?

Can I choose which columns to check for duplicates?

Yes! By default, we check all columns, but you can specify specific columns. For example:

This would only check the "name" and "email" columns for duplicates, ignoring other columns like dates or IDs that might be different.

How long does processing take?

Processing time depends on file size:

• Small files (< 1MB): Usually under 5 seconds
• Medium files (1-10MB): 10-30 seconds
• Large files (10-100MB): 1-5 minutes

Is my data secure?

Yes, we take data security seriously:

• Files are processed on secure servers with encryption
• No human personnel access your data during processing
• All files are immediately deleted after download
• We never store or share your data with third parties

For complete details, read our comprehensive privacy policy.

How long are my files stored?

Your uploaded files and processed results are immediately deleted after you download them. This ensures maximum privacy and security. Learn more about our data handling in our privacy policy.

Can I delete my files immediately after processing?

Files are automatically deleted immediately after download. You can use the "Process Another File" button to start fresh, which will clear your current session data from the interface.

My file upload failed. What should I do?

Try these solutions:

• Check that your file is under 100MB
• Ensure the file has a .csv or .txt extension
• Try refreshing the page and uploading again
• Check your internet connection
• Try using a different browser

The processing failed with an error. What went wrong?

Common issues and solutions:

• Invalid CSV format: Check that your file has proper CSV structure
• Empty file: Make sure your file contains data
• Column names don't exist: Verify column names in the options match your file headers
• File corrupted: Try re-saving and re-uploading your file

No duplicates were found, but I know there are duplicates. Why?

This might happen because:

• Case sensitivity: Try unchecking "Case sensitive" if your duplicates differ only by case
• Extra spaces: Our tool is sensitive to extra spaces - "John Smith" ≠ "John Smith"
• Column selection: Make sure you're checking the right columns for duplicates
• Data formatting: Check for hidden characters or inconsistent formatting

The download isn't working. How can I get my processed file?

Try these steps:

• Check if your browser is blocking downloads
• Try right-clicking the download button and selecting "Save link as"
• Disable browser extensions that might interfere
• Clear your browser cache and try again
• Try a different browser