Remove Duplicate Rows from CSV Online Free — No Upload
Remove duplicate rows from CSV entirely in your browser — deduplicate by all columns or by a specific column like email or ID. Keep first or last occurrence. No upload, no signup, no file size limits.
How it works
- Drop or select your CSV file — it opens instantly on your device.
- Choose "compare all columns" or pick specific columns to detect duplicates.
- Click Remove Duplicates and download your cleaned file.
Frequently asked questions
Is my CSV file uploaded to a server?
No. This tool runs 100% in your browser. Your file is read locally by your own device and never transmitted anywhere — verify it in DevTools (Network tab shows zero requests) or disconnect your internet before use.
How do I remove duplicates based on one column only?
Select the mode "Rows share a value in selected column(s)" and tick the column (e.g. email, user ID). Any rows with a repeated value in that column are treated as duplicates, keeping the first occurrence by default.
What is the maximum file size?
There is no artificial limit — no paywall at 5MB or 10MB like many competitors. The only constraint is your device's memory, which handles files with millions of rows on most modern computers.
Does it handle quoted fields with commas inside?
Yes. Parsing is fully RFC 4180 compliant: quoted fields may contain commas, escaped quotes and literal line breaks without corrupting your data.