Text and list tool
Duplicate Line Remover
Remove repeated lines while keeping the first occurrence and original order. Choose comparison rules without uploading your text.
The first time a line appears it is kept. Later copies are removed.
How to remove duplicate lines
Add text and remove duplicates
Enter line-based text into the input field. All toggles start in the off position, which means the tool uses exact comparison. Click Remove duplicates to process the text, then use Copy result to transfer the cleaned result to your clipboard. Empty or whitespace-only input shows "Add some text before removing duplicates."
Choose comparison rules
Leave all toggles off for exact comparison, or enable any combination of Ignore case, Ignore surrounding whitespace, and Remove blank lines. Each toggle change recomputes the result immediately whenever your input is not empty.
Copy result and Clear text
Copy result writes the cleaned text to your clipboard when you click it. Clear text removes all input and output, restores the default comparison options, and returns focus to the input field.
How first-occurrence removal works
Exact comparison and original order
When all options are off, the tool keeps the first exact occurrence of each line and removes all later duplicates. The output preserves the original order—it is never sorted or otherwise reordered.
Ignore case
When enabled, comparison ignores uppercase and lowercase. The first occurrence's original casing is always kept in the output; only the comparison changes.
Ignore surrounding whitespace
When enabled, comparison trims spaces before and after a line. The kept first line is never trimmed or rewritten—only the comparison key is trimmed.
Remove blank lines
When off, blank lines are treated as ordinary lines and participate in deduplication like any other. When enabled, blank lines are removed in addition to duplicates.
Worked comparison example
Default exact comparison
Input (six lines):
- 1. Apple
- 2. apple
- 3. Apple (one leading and one trailing space)
- 4. (empty line)
- 5. Banana
- 6. Apple
Output: Apple, apple, Apple (with spaces), empty line, Banana — 1 duplicate removed, 0 blanks removed, 5 lines remain.
Case and whitespace options
With Ignore case only: Apple, Apple (with spaces), empty line, Banana — 2 duplicates removed, 0 blanks removed, 4 lines remain.
With Ignore surrounding whitespace only: Apple, apple, empty line, Banana — 2 duplicates removed, 0 blanks removed, 4 lines remain.
All three options
With all three enabled: Apple, Banana — 3 duplicates removed, 1 blank removed, 2 lines remain.
In every outcome, the kept Apple is the exact first line, preserving its original text and position.
Line endings, counts, and limits
Line endings and trailing newlines
The tool accepts Windows (CRLF), old-Mac (CR), and Unix (LF) line endings and splits on all three. Output always uses LF. A single trailing newline is removed before comparison, so one trailing newline does not create an extra blank line. Two trailing newlines leave one ordinary blank line to process.
What the status counts mean
The status reports the number of duplicate lines removed, the number of blank lines removed (if that option is enabled), and the number of lines remaining in the output.
Line-based uses and practical limits
This tool works on whole lines only. It is useful for simple lists, log excerpts, and plain-text exports. The tool compares whole lines; it does not understand CSV quoting, columns, fields, headers, or records. Capacity and speed depend on your browser and device—no fixed maximum or arbitrary large-list performance is promised.
Private, browser-based line cleanup
Input text and the cleaned result are processed in this browser. They are not uploaded or sent to a 247 Tools server, and the tool does not save cleanup history. Copy result writes only the current result to your system clipboard when you choose it. Clear text removes the current text and result, restores the default comparison options, and refocuses the input; it does not clear the system clipboard.