重複行削除

This tool removes duplicate lines from any list or block of text. By default it keeps the first occurrence of each line in its original position and drops the later repeats, so the order you had is preserved.

It is the quick fix for messy lists: deduplicating an email or address list, cleaning an export, collapsing repeated log lines, or tidying a keyword list where the same term crept in several times.

The processing happens entirely in your browser, so even long lists are handled instantly and nothing you paste is uploaded.

Matching is exact by default, comparing the whole line character for character. That makes it predictable: two lines count as duplicates only if they are truly identical, unless you loosen the rules with the options below.

Trim ignores leading and trailing spaces, turning off case-sensitivity treats "Apple" and "apple" as the same line, and you can drop empty lines so blank rows do not survive.

You can also sort the result alphabetically if order does not matter and you would rather have a clean, sorted list than the original sequence.