Remove Duplicate Lines Online Free
Paste any list of lines and instantly remove all duplicates. Keep the first or last occurrence, optionally ignore case and leading/trailing whitespace, sort alphabetically, and download the clean result. Stats show how many lines were removed and the reduction percentage. All processing is done locally in your browser.
100% private. All text processing happens in your browser. Nothing is sent to any server.
How to Remove Duplicate Lines Free
- 01
Paste your text
Paste any list of lines into the input area. Click "Load sample" to try a pre-loaded example with duplicates.
- 02
Set options and process
Choose case sensitivity, whitespace trimming, and sort preferences. Click the action button that matches what you need.
- 03
Copy or download
The deduplicated result appears in the output area. Copy to clipboard or download as a .txt file.
Frequently Asked Questions
What does "Remove Duplicate Lines" do?
It takes any block of text, splits it into individual lines, identifies lines that appear more than once, and removes the duplicate occurrences — leaving only unique lines. You can choose to keep the first or last occurrence of each duplicated line.
What is the difference between "keep first" and "keep last"?
When keeping the first occurrence, the first time a line appears it is kept and all subsequent duplicates are removed. When keeping the last occurrence, all earlier duplicates are removed and the final occurrence of each line is kept. Both produce the same set of unique lines but in a different order.
Does case sensitivity matter?
With case sensitivity ON (the default), "Apple" and "apple" are treated as different lines and both are kept. With case sensitivity OFF, they are treated as duplicates and only one is kept. The original casing of the kept line is preserved in the output.
What does "trim whitespace before comparing" do?
When enabled, leading and trailing spaces are stripped from each line before comparison. So " apple " and "apple" would be treated as duplicates. The output retains the original line (with whitespace) from the kept occurrence.
Can I sort the result alphabetically?
Yes. Enable the "Sort result alphabetically" option to sort the deduplicated output in A→Z or Z→A order. Sorting happens after deduplication, so the output contains only unique lines sorted in the chosen direction.