Remove Duplicate Lines
Delete duplicate lines from any list — keep first occurrences, count what you removed.
The Remove Duplicate Lines tool strips repeated lines from any list while preserving the order of first occurrences. Paste a mailing list, tag dump, log extract, CSV column or any multi-line text, and every duplicate disappears — with an exact count of how many lines were removed.
Real-world lists accumulate duplicates constantly: exports merged twice, copy-paste errors, tags collected from multiple sources, or log lines repeated across runs. Manual deduping is error-prone at scale; this tool handles thousands of lines instantly with optional trimming and case-insensitive matching ('Apple' and 'apple' treated as the same).
Processing is local and instant — your list never leaves the browser. Empty lines are skipped by default (toggle to keep them) and the result is one click from your clipboard.
How to use the Remove Duplicate Lines
- Paste your list, one item per line.
- Toggle 'Trim spaces' if lines carry stray indentation.
- Toggle 'Ignore case' if 'Apple' should equal 'apple'.
- Read the result with counts of lines kept and removed.
- Copy the deduplicated list.
Frequently asked questions
Does this change the order of my lines?
No — the first occurrence of each line keeps its original position and later duplicates are removed. If you also need alphabetical order, run the result through the Text Sorter afterwards.
What counts as a duplicate?
Two lines that are identical after applying your options. With 'Ignore case' off, 'apple' and 'Apple' are different lines and both survive; with it on, only the first stays.
Will it work on very long lists?
Yes — the tool processes text locally and can handle tens of thousands of lines comfortably in the browser. Extremely large files may slow the page, as with any client-side tool.
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