Remove Duplicate Lines
Remove duplicate lines from lists, code, and text blocks instantly. Features case sensitivity toggles, line trimming, blank line removal, and alphabetical sorting.
How to Use the Remove Duplicate Lines
Paste your list into the input box and configure your options (trim whitespace, case sensitivity, remove blank lines, or sort). The deduplicated list is generated immediately for copying or downloading.
Calculation Examples
Simple Duplicate Elimination
2 duplicate lines eliminated; original list order preserved.
Case-Insensitive Deduplication
Matches duplicate entries regardless of capitalization.
Frequently Asked Questions
Can this tool process very long lists?
Yes. The deduplication algorithm operates in linear O(N) time with in-memory hashing, handling tens of thousands of lines smoothly in modern web browsers.
Is my data stored or sent anywhere?
Never. All processing happens exclusively inside your local browser memory. No data is stored, cached, or uploaded.
Can I preserve the original line ordering?
Yes. By default, the first occurrence of each unique line is kept in its exact original order.