Duplicate Line Remover – Remove Duplicate Text Free

Case-sensitive matching treats "Apple" and "apple" as two different items — both are kept. Case-insensitive matching treats them as the same — only one is kept based on your "keep first/last" setting. For most practical purposes like deduplicating email lists or keyword lists, case-insensitive is recommended. For code or data where case matters, use case-sensitive mode.

When duplicates are found, "Keep First" retains the first occurrence of an item and removes all later copies. "Keep Last" does the opposite — it removes all earlier copies and keeps only the final occurrence. For most list deduplication tasks, "Keep First" is the standard choice. "Keep Last" is useful when your list has updates and the most recent entry is at the bottom.

CSV mode splits your text by a separator character (comma, semicolon, pipe, tab or custom) instead of by lines. This is useful for cleaning a single row of data like "apple, banana, apple, cherry" where you want to get "apple, banana, cherry". You can also choose how to join the output — back to comma-separated, pipe-separated, or one item per line.

This tool runs entirely in your browser using JavaScript and can handle tens of thousands of lines efficiently. For very large datasets (100,000+ lines), processing may take a second or two depending on your device. There is no server upload limit since everything runs client-side. For extremely large files (megabytes), consider splitting the data before pasting.

Yes! After removing duplicates, the tool shows a "Duplicates Found" report listing each duplicated item along with how many times it appeared. This gives you full visibility into what was removed. Items that appeared only once are not shown in the report — only the ones that had 2 or more occurrences.