Remove Duplicate Lines

Paste any list or text — the tool removes duplicate lines instantly. Supports case-insensitive matching, trimming whitespace, removing empty lines, and sorting.

Input 0 lines
Output (deduplicated) 0 lines
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Paste your text and click Remove Duplicates to clean up your list.
How to Use

Paste your list into the input box — one item per line. Toggle the options below to customize how duplicates are detected and the output is formatted.

Click Remove Duplicates to process your text. The deduplicated result appears in the output box. The stats show how many lines were in the input, output, and how many duplicates were removed.

Copy or swap — Use the Copy button to copy the result to your clipboard, or Swap to exchange input and output panes.

Options Explained

Case-insensitive — Treats "Hello" and "hello" as duplicates. Useful for cleaning lists where capitalization varies.

Trim whitespace — Removes leading and trailing spaces from each line before comparison. Prevents "apple" and " apple " from being treated as different lines.

Remove empty lines — Strips blank lines from both input and output for a cleaner result.

Sort alphabetically — Sorts the deduplicated lines in alphabetical order (A→Z).

Reverse order — Reverses the output order. Useful with sorting for Z→A ordering.

Add line numbers — Prepends each line with its line number (e.g., "1. item").

How It Works

The tool processes your text line by line. It normalizes each line based on your selected options (trimming, lowercasing) and keeps only the first occurrence of each unique line. The first occurrence is preserved; all subsequent identical lines are removed. Everything runs locally in your browser — no data is sent to any server.

Frequently Asked Questions

Is this tool free to use?

Yes, this tool is completely free to use. No registration, no login, and no subscription required. Just open the page and start using it.

Is my data safe? Is anything stored on a server?

Yes, your data is safe. All processing happens entirely in your browser — your input never leaves your device and is not sent to any server. There are no analytics, no tracking, and no data collection.

Does this tool work on mobile devices?

Yes. The tool is fully responsive and works on smartphones, tablets, and desktop computers. On smaller screens, the input and output panes stack vertically.

What counts as a duplicate line?

By default, two lines are considered duplicates only if they are exactly the same, including whitespace. Enable Case-insensitive and Trim whitespace options for more flexible matching.

Can I remove duplicates from a CSV or spreadsheet data?

Yes. Simply paste the column data into the tool, one value per line. However, for CSV files with multiple columns, you may need to extract the relevant column first.

Is there a limit on file size?

The tool processes everything in your browser's memory. For most practical use cases (thousands of lines), it works instantly. For extremely large files (100,000+ lines), your browser may take a moment to process.

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