Duplicate Line Remover
Strip repeated lines out of a list, keeping the first occurrence of each. Options let you ignore capitalisation, trim stray spaces before comparing, and sort the result alphabetically — which together handle most of the mess that comes from combining lists copied out of different places.
How to remove duplicate lines
- Paste your list — one item per line.
- Choose whether to ignore case, trim spaces, or sort the result.
- Tap Remove duplicates and copy the cleaned list.
When you'd use this
- Merged mailing lists — Two lists of email addresses combined, with overlap between them.
- Keyword lists — Removing repeats from a list built up over several sessions.
- Data cleanup — Tidying a column pasted out of a spreadsheet before using it.
- Any combined list — Names, URLs, product codes — anything one per line.
Good to know
- The first occurrence is kept — Duplicates after the first are removed, so the original ordering of what remains is preserved unless you sort.
- Ignore case catches more — With it on, Apple and apple count as the same line. Leave it off when capitalisation is meaningful.
- Trim spaces catches invisible duplicates — Lines that differ only by a trailing space look identical but are not. Trimming compares them properly, which is usually what you want.
- Works line by line — Each line is one item. Text separated by commas needs to be one-per-line first.
Frequently asked questions
Which copy of a duplicate is kept?
The first one, in its original form. With “Ignore case” on, “Apple” and “apple” count as the same line and whichever appeared first is kept.
What does “Trim spaces” do?
It strips spaces from the start and end of every line before comparing, so “item ” and “item” are treated as the same. It's on by default because invisible trailing spaces are the most common reason duplicates seem to “survive”.
Does my list leave the browser?
No — everything runs on your device. Nothing is uploaded, logged or stored.
Does it keep the original order?
Yes, unless you tick sort. The first occurrence of each line stays where it was and later duplicates are dropped.
How do I remove duplicates from a comma-separated list?
Replace the commas with line breaks first, since the tool compares whole lines. Most text editors and spreadsheets can do that in one step.
Are blank lines removed?
Repeated blank lines collapse like any other duplicate. Turning on trim spaces also catches lines that contain nothing but spaces.