Remove Duplicate Lines
Runs entirely in your browser
Remove duplicate lines from a list or block of text while keeping the first occurrence and original order. Everything happens directly in your browser.
How to use Remove Duplicate Lines
- Paste your list or block of text into the Input box.
- Choose whether to trim lines and whether matching should be case-sensitive.
- Click Remove Duplicates.
- The de-duplicated result appears in the Output box — copy it with one click.
Features
- Removes duplicate lines while keeping the first occurrence and original order.
- Optional case-sensitive matching.
- Optional trimming of leading and trailing spaces before comparing.
- 100% client-side — your text never leaves your browser.
Example
With the default options (trim lines on, case-sensitive off), this input:
apple
Apple
banana
apple
cherry
bananabecomes:
apple
banana
cherryOriginal lines: 6 · Unique lines: 3 · Duplicates removed: 3. "Apple" was treated as a duplicate of "apple" because case-sensitive matching was off, and the trailing space on the second "apple " was ignored because trimming was on.
Tips for cleaning up lists
- Comparison happens on the whole line, not on individual words — a line that merely starts with the same words as another isn't treated as a duplicate unless it matches completely.
- Turn on case-sensitive matching if your list depends on capitalization, such as variable names or codes where "ABC" and "abc" need to stay separate.
- The first occurrence of each line is always the one kept, and the surviving lines stay in their original order — if you also want the result alphabetized, run it through Text Sorter afterward.
Is Remove Duplicate Lines safe?
Yes. Remove Duplicate Lines compares each line locally using the case-insensitive, trim-aware matching described above, so your list is never uploaded to a server, and nothing is kept once you close or refresh the tab.
Frequently Asked Questions
Does this keep the original line order?
Yes. The first occurrence of each line is kept in place and later duplicates are removed, so the remaining lines stay in their original order.
Can I ignore case when comparing lines?
Yes. By default the comparison ignores case, so "Apple" and "apple" are treated as duplicates. Turn on case-sensitive matching if you want them treated as different lines.
What does 'trim each line before comparing' do?
It ignores leading and trailing spaces when checking for duplicates, so "apple" and "apple " are treated as the same line.