Remove Duplicate Lines
Clean up your text by removing duplicate and empty lines
Input
Output
How the Duplicate Remover Works
This tool processes your text line by line, keeping only the first occurrence of each unique line. It uses a hash set for fast duplicate detection. You can customize behavior with options for case sensitivity, whitespace trimming, alphabetical sorting, and empty line removal. All processing happens in your browser.
Common Use Cases
Removing duplicate lines is useful for cleaning up email lists, log files, data exports, spreadsheet columns, keyword lists, URL lists, and any other line-based data. Developers commonly use it to deduplicate configuration entries, DNS records, or test data. Content creators use it to clean up keyword research exports.
Understanding the Options
Case-sensitive mode treats "Hello" and "hello" as different lines. Trim whitespace removes leading and trailing spaces before comparing, which catches lines that look identical but have extra spaces. Sort lines alphabetically organizes the output. Remove empty lines cleans up blank lines that often appear in pasted data.