Remove Duplicate Lines
Paste multi-line text and instantly get back the same text with duplicate lines removed. Only the first occurrence of each line is kept; subsequent duplicates are stripped out, preserving the original order of the remaining lines.
Two toggle options let you control how duplicates are detected: case-sensitive matching (so 'Hello' and 'hello' are treated as different lines, or the same) and whitespace trimming (so lines with leading/trailing spaces match their trimmed equivalents, or don't). The tool shows exactly how many duplicate lines were removed.
Useful for cleaning up lists, log files, CSV exports, email lists, and any other text where repeated lines need to go. Everything runs in your browser — your text is never sent anywhere.
By The Paper Room Editorial Team — Text & Formatting Tools
Frequently asked questions
Does this preserve the original line order?▼
Yes — the first occurrence of each line stays in its original position. Only the second and subsequent occurrences are removed. The output is in the same order as the input, minus the duplicates.
What does the 'trim whitespace' option do?▼
When enabled, leading and trailing spaces (and tabs) are stripped from each line before comparing. This means ' hello ' and 'hello' are treated as duplicates. The output uses the trimmed version. When disabled, whitespace differences make lines unique.
Can I remove duplicate lines from a CSV file?▼
You can paste CSV content here and it will remove lines that are exact textual duplicates. However, it compares entire lines as strings — it won't detect rows that have the same data but different column orders or quoting. For structured CSV deduplication, use a spreadsheet tool.