Paste CSV data or upload a file
Paste comma-separated data into the input box or upload a CSV file using the upload area.
Free CSV Deduplicator
CSV Deduplicator
Remove duplicate rows from a CSV instantly in your browser. Paste CSV data or upload a file, choose how to deduplicate it, and get a clean CSV in seconds. Fast, free, and private.
Paste CSV data or upload a file. Select whether the first row is a header and how duplicates should be detected.
Or upload a CSV file
Processed entirely in your browser
Results
Files are processed entirely in your browser and are never uploaded to any server.
How it works
How to Deduplicate a CSV
Everything runs in your browser. No account, no software, no data leaving your device.
Choose how to identify duplicates
Indicate whether the first row is a header, then choose exact duplicate rows or duplicates based on selected columns.
Click Remove Duplicates
The tool keeps the first occurrence of each duplicate and shows a summary of rows removed.
Copy or download the cleaned CSV
Copy the result to your clipboard or download it as a CSV file.
Why use this tool
Why Use a CSV Deduplicator?
Removing duplicate rows keeps your data clean and easier to work with. A CSV deduplicator helps you prepare exports for import, strip repeated records, and avoid errors from duplicate entries.
Clean exports before import
Remove repeated records so databases and tools receive unique rows only.
Prepare data for Excel or Sheets
Deduplicate before opening in spreadsheets or feeding into scripts.
Reduce errors from duplicates
Avoid double-counting or conflicting rows in analysis and imports.
Keep datasets smaller
Smaller, duplicate-free files are easier to share and process.
Privacy
Private and Secure CSV Deduplication
Your files and pasted data are never uploaded to a server. This CSV deduplicator runs entirely in your browser using client-side processing.
Data stays on your device
Your data never leaves your browser. No uploads, no cloud storage, no logs.
Nothing stored or sent
No files are stored or transmitted. Deduplication happens only in memory.
Fast and private
Deduplication is instant and runs locally at full browser speed.
FAQ
Frequently asked questions
In exact mode, two rows are duplicates if every cell matches. In column mode, two rows are duplicates if the values in the columns you selected are the same. The first occurrence is kept; later duplicates are removed.
Yes. Choose “Duplicate values in selected columns” and select a single column (for example, email). Rows with the same value in that column are treated as duplicates; the first is kept.
Yes. If you check “This file has a header row,” the first row is always kept as the header and is not considered when finding duplicates.
No. Everything runs locally in your browser.
Yes. The CSV deduplicator is free to use with no signup required.
Yes. The output is standard CSV with proper escaping for commas and quotes, so it works in Excel, Google Sheets, and other spreadsheet tools.
The parser handles quoted fields correctly. Values that contain commas, quotes, or newlines are read as single cells, and the output re-escapes them so the CSV stays valid.