What this tool helps you find
Paste a list and choose whether matching should respect letter case, trim whitespace, and remove blank lines. The first occurrence of each line is kept.
Formula
Each line is compared according to the selected case and whitespace options; the first occurrence is kept.
Worked example
“pear apple pear” becomes “pear apple”.
Common mistake
If whitespace trimming is off, lines with extra spaces are considered different. If case sensitivity is on, “Pear” and “pear” are also different.
When to use it
Clean copied lists, remove repeated IDs, or prepare unique values for a spreadsheet.
Questions and answers
Which duplicate is kept?
The first occurrence is retained and later duplicates are removed.
Does text leave my device?
No. Line processing is performed locally in your browser.