Remove Duplicate Lines from Any Text
Remove duplicate lines from any list or block of text and keep only the unique ones. Paste your text on the left and the deduplicated result appears on the right instantly — no button to press, nothing to install.
Choose how lines are matched (exact, case-insensitive, or ignoring extra spaces), decide whether to keep the first or last occurrence, and optionally sort the output A→Z or Z→A. A live counter shows how many duplicates were removed, and a Removed Lines panel lists exactly what was taken out.
It is built for anyone who works with text data — analysts cleaning CSV columns, developers deduping log files or config lists, marketers tidying email and contact lists, and writers organizing keyword or reference lists.
How to Remove Duplicate Lines
Enter your text
Type or paste your text into the Input panel, one item per line. You can also click the Paste button to pull text straight from your clipboard. Results update in real time as you type.
Choose how lines are compared
Open the Comparison menu and pick Case Sensitive, Case Insensitive, Trim Whitespace, or Trim + Case Insensitive. Then set Keep to First or Last to decide which occurrence stays.
Sort and refine (optional)
Use the Sort menu to leave the output in its original order (None) or sort it A → Z / Z → A. Tick Ignore Empty so blank lines are skipped during comparison and kept in the result.
Copy or download the result
The unique lines appear in the Output panel. Click Copy to send them to your clipboard or Download to save a unique-lines.txt file. Open the Removed Lines panel to review what was deleted.
Features
Real-Time Processing
Duplicates are detected and removed as you type or paste — no button to press. Debounced updates keep it smooth even with large lists.
Flexible Comparison Modes
Match lines four ways: Case Sensitive, Case Insensitive, Trim Whitespace, or Trim + Case Insensitive for messy data.
Keep First or Last Occurrence
Decide which duplicate survives — keep the first time a line appears or the most recent one.
Visual Duplicate Highlighting
Duplicate lines are flagged with yellow line numbers in the input, so you can spot repeats at a glance.
Removed Lines Panel
A collapsible panel lists every removed line with its original line number, and a Copy All button grabs them in one click.
Live Statistics
A stats bar shows Total lines, Unique lines, Duplicates removed, and the Reduction percentage in real time.
Optional Sorting
After deduplication, sort the unique lines A → Z or Z → A, or keep the original order.
Ignore Empty Lines
Skip blank lines during comparison so they are never treated as duplicates and stay in your output.
Copy & Download
One-click Copy to clipboard or Download the result as a plain-text file named unique-lines.txt.
Saved Preferences
Your comparison mode, keep setting, sort choice, and empty-line option are remembered for your next visit.
Frequently Asked Questions
Does it keep the original line order?
Yes. By default the Sort option is set to None, so unique lines stay in the order they first appeared. Only switch to A → Z or Z → A if you want the output reordered.
Is the comparison case-sensitive (Apple vs apple)?
It is by default. In Case Sensitive mode, "Apple" and "apple" are treated as different lines. Switch the Comparison menu to Case Insensitive (or Trim + Case Insensitive) to treat them as the same and remove one as a duplicate.
What does Trim Whitespace do?
It ignores spaces and tabs at the start and end of each line when matching, so " Hello " and "Hello" count as duplicates. The kept line keeps its original spacing in the output — only the comparison ignores it. This is handy for data copied from different sources.
What is the difference between Keep First and Keep Last?
Keep First keeps the earliest occurrence and removes the ones after it. Keep Last keeps the final occurrence and removes the earlier ones. For example, with lines A, B, A, C, A: Keep First gives A, B, C; Keep Last gives B, C, A.
Does it also remove blank or empty lines?
By default empty lines are compared like any other line, so repeated blanks are reduced to one. Tick Ignore Empty in the toolbar to skip blank lines during comparison — they are then never flagged as duplicates and all of them stay in your output.
How do I remove duplicate lines from a text file?
Open your file, copy its contents, and paste them into the Input panel (or use the Paste button). The unique lines appear in the Output panel, where you can click Download to save them as a new unique-lines.txt file or Copy them back into your document.
Can I see and recover what was removed?
Yes. Your original text in the Input panel is never changed — only the Output shows the deduplicated result. Open the collapsible Removed Lines panel to see each removed line with its original line number, and use Copy All to copy them if you need them back.
Is there a line or character limit?
There is no fixed limit built into the tool. Because everything runs in your browser, the practical ceiling depends on your device's memory. Most modern browsers handle hundreds of thousands of lines fine, though very large inputs may take a moment to process.
Are there keyboard shortcuts?
Yes. Press Ctrl+V in the input area to paste, Ctrl+Shift+C to copy the output, and Ctrl+Shift+X to clear everything. On Mac, use Cmd in place of Ctrl.
Is my text uploaded to a server?
No. All processing happens locally in your browser using JavaScript. Your text is never uploaded, stored, or transmitted anywhere, which makes the tool safe for sensitive lists. Only your settings (comparison mode, keep, sort, and empty-line option) are saved locally for next time.
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