About the Remove Duplicate Lines
Cleaning up a list by hand is slow and error-prone. The Remove Duplicate Lines tool scans your text line by line and keeps only the first occurrence of each entry, while preserving the original order of everything else.
It is ideal for de-duplicating email lists, keywords for SEO research, product SKUs, URLs, usernames, log files and CSV columns. Enable Ignore case to treat "Apple" and "apple" as the same, Trim whitespace to ignore stray spaces at the start or end of lines, and Remove empty lines to tidy the output. You can also sort the result alphabetically and download it as a text file.
Example: cleaning an email list
Imagine this list collected from two sign-up forms:
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]With Ignore case, Trim whitespace and Remove empty lines switched on, you get:
[email protected]
[email protected]
[email protected]The first spelling of each address is kept, the second "sara" with a leading space is recognised as a duplicate, and the empty line is gone.
Other everyday uses
- Keyword research: combine keyword lists from several tools and remove repeats before you analyse them.
- URL lists: clean a list of pages before creating an XML sitemap.
- Inventory and SKU lists merged from different suppliers.
Tip: for values separated by commas, first turn the commas into new lines with Find and Replace (replace , with \n), then remove duplicates.
How to use the Remove Duplicate Lines
- Paste your list with one item per line.
- Choose whether to ignore case, trim whitespace, remove blanks or sort.
- See the unique lines and how many duplicates were removed.
- Copy the result or download it as a .txt file.
Frequently asked questions
Does it keep the original order?
Yes. Unless you enable Sort result, the first occurrence of each line stays in its original position.
How many lines can it handle?
Hundreds of thousands of lines are processed in a fraction of a second because the tool uses an efficient hash set.
Can I de-duplicate comma-separated values?
Put each value on its own line first. You can use our Find and Replace tool to replace commas with line breaks.