Remove Duplicate Lines

How duplicate removal works

Paste your list, choose your comparison options, and select "Remove Duplicates." Each line is compared against every line seen before it — the first occurrence is kept, every later repeat is removed.

Case sensitivity and whitespace trimming

With case-sensitive comparison on, "Apple" and "apple" are treated as different lines. With whitespace trimming on, "apple" and "apple " (trailing space) are treated as the same line — turn these on or off depending on how strict you need the match to be.

Common Mistakes to Avoid

Leaving case sensitivity on when it shouldn't matter

Solution:

If "Apple" and "apple" should count as the same entry, turn case sensitivity off before processing.

Not trimming whitespace before comparing

Solution:

A trailing space can make two otherwise-identical lines appear different — enable whitespace trimming to catch these.

Expecting line order to be preserved differently

Solution:

This tool keeps the first occurrence of each duplicate in its original position — it doesn't re-sort your list.

Frequently Asked Questions

The first one — every later repeat is removed.

Yes — toggle case-sensitive comparison on or off.

Optionally — toggle whitespace trimming before comparing lines.

No — everything runs locally in your browser.

Free Remove Duplicate Lines Tool

Paste a list, one item per line, and remove every duplicate — keeping the first occurrence of each unique line. Choose case-sensitive or case-insensitive comparison, and whether to trim whitespace before comparing.

What You Get

Removes duplicate lines, keeping the first occurrence
Optional case-sensitive or case-insensitive comparison
Optional whitespace trimming before comparing
Shows original count, unique count, and duplicates removed

Who Uses This Tool

Anyone cleaning up email lists, keyword lists, CSV exports, or any line-based data with repeated entries.