Duplicate Line Remover Online
Paste a newline-separated list and remove repeated lines while keeping the first or last occurrence. Choose whether case, edge spaces, and blank lines matter.
Written and checked by TheToolNet Editorial Team · Last reviewed: October 10, 2026 · Editorial method
Each line becomes one item. Exact repeats are removed in one pass, and retained lines stay in their original order.
Remove duplicate lines
Unique lines
Matching rules explained
With case-sensitive matching, Apple and apple are different. “Trim line edges” ignores leading and trailing spaces when comparing and returns trimmed lines. Blank-line removal is counted separately from duplicate removal.
The tool uses exact matching rather than fuzzy matching. Similar URLs with different tracking parameters, punctuation, or spelling remain separate because silently merging them could destroy useful data.
Worked example
Input: red · blue · red · RED
Ignore case off → red · blue · RED
Ignore case on → red · blueKeeping the first occurrence preserves the first spelling and position. Keeping the last retains the final spelling and position.
Frequently asked questions
Can it remove duplicate spreadsheet rows?
Yes for rows pasted as plain text, with one row per line. It does not understand individual CSV columns or quoted multiline fields.
Does it sort the result?
No. Deduplication preserves order. Use the related alphabetical list sorter when you also need sorting.
Is there a line limit?
The practical limit depends on browser memory. The algorithm is linear for ordinary pasted lists, but extremely large files are better handled by a desktop data tool.
Related text tools
Sort a list alphabetically · Remove line breaks · Remove spaces from text · Compare two texts