Remove Duplicate Lines Online
Delete repeated lines from a list while keeping the original order.
- Free
- Real-time
- Runs locally
Options
Mode
Keeps one copy of every line, in the original order.
Keep which copy
Lines
0
Distinct
0
Removed
0
Result
0
Most repeated
No duplicate lines found.
Clean up email lists, keyword lists, product SKUs, log files or any text with one item per line. Paste your list and every repeated line is removed instantly, while the remaining lines stay in their original order.
You decide what counts as a duplicate: match case exactly or ignore it, and ignore stray spaces that make identical lines look different. You can also flip the tool around to list only the lines that repeat, or only the lines that appear once. It all runs in your browser.
How to remove duplicate lines
- STEP 01
Paste your list
Put one item per line. You can paste thousands of lines from a spreadsheet, a text file or an export.
- STEP 02
Choose how to compare
Set case sensitivity and whitespace handling, decide whether to keep the first or last copy, and whether to drop empty lines.
- STEP 03
Copy the clean list
Copy or download the result, or use it as the new input to keep refining it.
Features
Keeps the original order
Duplicates are removed without sorting, so the list stays in the order you pasted it.
First or last occurrence
Keep the first time a line appears, or the last, which is handy for logs and updated records.
Case and spacing control
Treat “Apple” and “apple” as the same or different, and ignore leading, trailing and repeated spaces.
Find repeats or one-offs
Switch modes to list only duplicated lines or only lines that appear exactly once.
Duplicate report
Line, distinct, removed and result counts, plus a ranking of the most repeated lines.
Fast and private
Hundreds of thousands of lines are processed instantly in your browser, with nothing uploaded.
How lines are compared
Two lines are treated as duplicates when they match after these steps:
- Unicode normalization, so an accented letter typed in two different ways still matches.
- If “Ignore extra spaces” is on: leading and trailing spaces are removed and runs of spaces or tabs count as one.
- If “Case sensitive” is off: uppercase and lowercase letters are treated as equal.
- The kept line is shown exactly as it appeared in your input; only the comparison is normalized.
- Blank lines are never treated as duplicates. They stay in place, or are all removed when “Remove empty lines” is on.
Frequently asked questions
Does removing duplicates change the order of my list?
No. The remaining lines keep their original order. If you also want the list sorted, copy the result into a line sorting tool afterwards.
How do I remove duplicates regardless of uppercase and lowercase?
Turn off “Case sensitive”. Lines like “Apple”, “apple” and “APPLE” are then treated as one, and the copy you chose to keep (first or last) is shown as typed.
Why are two lines that look the same not removed?
They probably differ in invisible ways, such as trailing spaces, tabs or letter case. Keep “Ignore extra spaces” on and try turning off “Case sensitive”.
Can I see which lines were duplicated?
Yes. The Most repeated panel ranks lines that appear more than once with their counts, and the Only duplicates mode outputs one copy of each repeated line.
How many lines can I process?
There is no fixed limit. Lists with hundreds of thousands of lines are handled in a fraction of a second on a typical computer.
Is my list uploaded anywhere?
No. Everything happens in your browser, so lists with emails or customer data never leave your device.