Duplicate line finder

Two lines match when they are identical after leading and trailing whitespace is stripped. The comparison is case-sensitive, so "Apple" and "apple" are two different entries. Blank lines are ignored entirely rather than counted as a repeated empty value.

Both. The result is your list with every repeat collapsed to a single row, so copying or exporting it gives you a de-duplicated list. Each row also carries the number of times that line appeared, so you can see what was removed rather than having to trust it.

Sorted by count, most repeated first, so the worst offenders are at the top. Lines that appeared only once follow. If you need the original order preserved instead, copy the result and sort it back in your spreadsheet.

Comfortably up to about 100,000 lines. Past 10,000 you will see a notice, because the work happens on your own machine and a slower device will pause noticeably. Results are paginated at 100 rows so the page stays responsive regardless.

No. Everything runs in your browser. Nothing is uploaded, stored or logged, which is what makes this safe for client exports, email lists and anything else you would not paste into an unknown server.