ToolFoxDuplicate Line Remover
Remove duplicate lines from a list while keeping the first occurrence of each line, in order.
How it works
Each line of your text is compared against every line seen so far; the first time a line appears it is kept, and any later repeat of the exact same line is dropped. The case-insensitive mode compares lines after lowercasing them (so "Apple" and "apple" count as the same line) but keeps the original casing of whichever occurrence came first — the order of the remaining lines is never changed.
Example
Pasting the five lines a, b, a, c, b (one per line) produces just three lines — a, b, c — each kept once, in the order it first appeared; handy for cleaning up an email list or a log file with repeated entries.
Frequently asked questions
Does it preserve the original order?
Yes — the first occurrence of each line stays exactly where it was; nothing is re-sorted, only later repeats are removed.
What counts as a duplicate in case-insensitive mode?
Lines that are identical once lowercased, such as "Apple" and "apple" — the version that appears first in the text is the one kept, casing included.
Does it ignore leading or trailing spaces?
No — lines are compared exactly as typed (aside from case, in case-insensitive mode), so " apple" and "apple" are treated as different lines.
Is my text uploaded anywhere?
No — deduplication runs entirely in your browser as you type.
Related tools
Count words, characters, sentences and paragraphs instantly, with an estimated reading time.
Case ConverterConvert text between UPPER, lower, Title, Sentence, camelCase, snake_case and kebab-case.
Text Diff CheckerCompare two blocks of text line by line and see exactly what was added, removed or changed.