Remove Duplicate Lines

Remove duplicate and repeated lines from text instantly — keep first occurrence or last, with optional sorting.

About Remove Duplicate Lines

Removing duplicate lines is a common data cleaning task. When importing data from spreadsheets, merging lists, processing log files, or combining text from multiple sources, duplicate entries are a frequent problem. This tool removes duplicate lines, keeping only the first occurrence of each unique line, while preserving the original order.

The case-insensitive option treats "Apple", "apple", and "APPLE" as duplicates. The trim option removes leading and trailing whitespace before comparison, so " hello " and "hello" are treated as duplicates. Together, these options handle the messy real-world data that comes from CSV exports, form submissions, and copy-pasted lists.

FAQ

Does this preserve the original order?
Yes. The first occurrence of each unique line is kept in its original position. Subsequent duplicates are removed. Use the Sort Lines tool if you want the output alphabetically ordered.
Can I use this for CSV deduplication?
Yes, for simple CSV deduplication where each row is on one line. For complex CSV with multi-line values or for deduplication based on specific columns, you'd need a more specialized CSV tool.