Remove Duplicate Lines
Delete duplicate lines from any list with options to trim, ignore case, keep the first or last occurrence, and drop empty lines.
Processed locally in your browser — nothing is uploaded.
Remove Duplicate Lines
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Deduplicated lines
Output appears here…About Remove Duplicate Lines
Paste a list — emails, URLs, log lines, anything with one entry per line — and get it back with duplicates removed and a count of what was dropped. Trimming and case-insensitive comparison catch near-duplicates like “Apple” and “ apple ”, and you can keep the first or the last occurrence of each entry.
Common uses
- Clean a mailing list of repeated addresses
- Deduplicate URLs collected from several sources
- Reduce noisy log output to its distinct lines
Frequently asked questions
Is my list kept private when I remove duplicates here?
Yes. Deduplication happens in your browser and the list is never transmitted or stored, which matters when the lines are email addresses, customer records, or log data.
Does removing duplicates change the order of my lines?
No. The remaining lines stay in their original order — by default the first occurrence of each duplicate survives, or the last one if you choose keep-last, but nothing is sorted.
How do I catch duplicates that differ only in spacing or capitalization?
Turn on trimming to ignore leading and trailing whitespace and case-insensitive comparison to treat "Apple" and "apple" as the same entry. With both on, " APPLE " and "apple" collapse into one line.
Does the tool also delete empty lines?
Only if you enable the drop-empty-lines option. Otherwise the first blank line is kept like any other line, and only repeated blanks are removed as duplicates of it.