Remove Duplicate Lines — Free Online Deduplicator

Remove Duplicate Lines — Clean Up Any List in Seconds

Paste any list and remove duplicate lines instantly. Whether you have an export with repeated emails, a CSV column with messy entries, or a brainstorming list with accidental duplicates, this tool removes the repeats and shows you exactly how many were dropped. Everything runs in your browser — your list never leaves your device.

How it works

• Each line is compared against every previous line
• The first occurrence is kept by default (configurable to last)
• Optional case-insensitive matching (“Apple” and “apple” treated as the same)
• Optional trim before comparison (so “apple ” and “apple” merge)
• Optional removal of empty lines
• Optional alphabetical sort of the result

What’s new vs basic dedupers

• Keep first or last: when the same line appears multiple times, choose which one survives
• Trim before compare: ” apple ” and “apple” count as duplicates
• Case toggle: “EMAIL”, “Email”, “email” — all the same or all different
• Statistics: see exactly how many lines came in, kept, and removed
• Order preserved by default: sorting is opt-in

Common uses

• Cleaning up email lists, contact exports, mailing lists
• Removing duplicate URLs, IDs, SKUs
• Brainstorm lists where the same idea was written twice
• Log file analysis: counting unique entries
• CSV preparation before database imports
• Removing repeated lines from a copy-paste mess

Privacy

This tool runs entirely in your browser. Your list is never uploaded.