Remove Duplicate Lines
Strip duplicate lines from multiline text with optional case-insensitive, trim, and sort controls.
0 lines in · 0 unique · 0 duplicates removed
O que é Remove Duplicate Lines?
A remove-duplicate-lines tool takes a block of multiline text and returns a version in which every line appears only once, keeping the first occurrence and dropping later repeats. Each line — delimited by a newline — is the unit of comparison, so duplicates inside a single line are untouched and the original order of first occurrences is preserved by default. The comparison can be made case-insensitive so that "Apple" and "apple" count as the same line, and leading or trailing whitespace can be trimmed before comparing so that " apple " matches "apple". An optional sort step reorders the surviving lines alphabetically. This is pure string processing — no regex, no network, no storage — which makes it fast on large inputs and safe for sensitive text.
Como usar Remove Duplicate Lines
- Paste or type the multiline text into the Input box.
- Toggle Case-insensitive if "Apple" and "apple" should count as the same line.
- Optionally enable Trim whitespace first and Sort result (A → Z).
- Copy the cleaned text from the Output box; the line below it shows how many duplicates were removed.
Exemplos
Default (order preserved)
Entrada: apple banana apple cherry banana
Saída: apple banana cherry
Case-insensitive
Entrada: Apple apple APPLE banana
Saída: Apple banana
Trim whitespace first
Entrada: banana banana cherry
Saída: banana cherry
Erros comuns
- Expecting deduplication to work across whole paragraphs rather than single lines — only exact per-line matches are removed.
- Enabling trim and then being surprised that original indentation is gone, since leading whitespace is stripped from every line.
- Assuming the case-insensitive toggle keeps the lowercase or uppercase form — it keeps the first casing it encountered.
- Forgetting that blank lines count as lines, so a trailing newline can produce an empty final entry in the output.
Por que usar esta ferramenta
- Order-preserving by default, so the logical structure of a list is not scrambled.
- Three independent toggles (case-insensitive, trim, sort) cover the common deduplication needs without a wall of options.
- A live count of input, unique, and removed lines makes the cleanup measurable at a glance.
- Runs entirely in the browser, so confidential text such as logs or keys never leaves the machine.