Duplicate Line Remover

Remove repeated lines from a text or list.

Duplicate Line Remover speeds up a small but time-consuming task that comes up often when working with text. Duplicate Line Remover completes this text task in seconds, without the manual back-and-forth. The whole process happens locally in your browser; nothing is sent to a server.

Step-by-step

Paste the list you want to clean into the Text field. Each item needs its own line. If it's comma-separated, split it into lines first.
Click Run.
Look over the result and compare its line count with the original to see how many duplicates were removed.
Copy the clean list into your spreadsheet, email tool or wherever it's going.

Example

You've collected email addresses from three sign-up forms for an event and merged them into one list. Anyone who filled in two forms appears twice and would get the invitation twice. Paste the list and run it, and each address is left once. A quick read before you send helps catch near-duplicates that differ only in spelling.

The same goes for keyword lists, product codes, IP addresses pulled from server logs, or a shopping list. As long as it's one item per line, the tool can handle it.

How are duplicate lines removed?

The tool splits the text into lines, keeps each line at its first appearance and removes later identical lines. The order of your list is preserved and only repeats are deleted.

Practical tips

Clean email, word or product-code lists before merging them.
The comparison is case-sensitive: Ali and ali count as different lines. If needed, bring the text to the same case first.
Leading and trailing spaces are ignored in the comparison, so "apple" and "apple " count as the same line and the first one seen is kept.

Common mistakes

Using it on a list where duplicates are deliberate (such as a tally).
Saving the result without keeping the original.
Being surprised that several blank lines collapse into one; blank lines count as repeats too.

Things to keep in mind

Two lines that look identical can count as different if one has a trailing space. If a duplicate you expected to disappear is still there, check the line endings.
Check the result to see how upper and lower case are handled. Ali@example.com and ali@example.com are the same mailbox but may stay as separate lines.
Blank lines are lines too. If your list has several, one may remain in the output.
Keep a copy of the original list before using the result, so you can go back if something was removed by mistake.