Duplicate Line Remover

Remove duplicate lines from text with flexible options. Keep first or last occurrence, ignore case, trim whitespace, and see statistics.

Remove duplicate lines from text with multiple options. Perfect for cleaning data, lists, and log files.

0 / 500,000
Result
Enter text to remove duplicates
Processes up to 500,000 characters. All processing happens in your browser — your data never leaves your device.

How to Use This Tool

  1. 1

    Paste your text

    Paste text with one item per line. This could be a list of names, emails, URLs, or any line-based data.

  2. 2

    Choose removal mode

    Select whether to keep the first occurrence, last occurrence, or remove all duplicate lines entirely.

  3. 3

    Set comparison options

    Choose exact match, trim whitespace (ignores leading/trailing spaces), or case-insensitive comparison.

  4. 4

    Copy the result

    Click Copy to get the cleaned text. Statistics show how many lines were total, unique, and removed.

Frequently Asked Questions

What does 'Keep first' vs 'Keep last' mean?
If a line appears multiple times, 'Keep first' preserves only the first occurrence, 'Keep last' preserves only the last. 'Remove all' deletes every instance of duplicated lines.
How does case-insensitive comparison work?
Lines are compared ignoring uppercase/lowercase differences. 'Hello' and 'HELLO' would be considered duplicates in this mode.
What happens to empty lines?
By default, empty lines are preserved (not considered for duplicate removal). Uncheck 'Ignore empty lines' to treat them as duplicates too.
Is there a size limit?
The tool handles up to 500,000 characters. For larger files, consider using command-line tools like 'sort -u' on Linux/Mac.