Remove Duplicate Lines
Strip out repeated lines and keep only the first of each, in order.
0 duplicate lines removed
About this tool
This tool strips repeated lines out of a list and keeps only the first appearance of each, leaving everything in its original order. Paste a block of lines in and you get a clean, de-duplicated version back.
Duplicate lines creep in whenever lists get combined. Merging two mailing lists produces repeated addresses; exporting data and pasting it together leaves duplicate rows; collecting URLs, keywords, tags or SKUs from several places almost always creates overlap. Scanning for repeats by eye is slow and unreliable, and sorting the list to group duplicates together destroys an order you might need to keep.
Keeping the first of each line and preserving order matters more than it sounds. If your list is arranged by priority, date or any deliberate sequence, you usually want the earliest entry retained and the rest removed — not the whole thing alphabetised. That's exactly what happens here: the first time a line appears it stays put, and any later identical lines are dropped.
The whole thing runs in your browser, so even a long list is de-duplicated instantly and nothing you paste is uploaded or stored.
Frequently asked questions
- Which duplicate does it keep?
- The first one. Each line is kept the first time it appears, and any later identical lines are removed, so the original order of your list is preserved.
- Does it sort the list?
- No. Sorting would change your order; this tool leaves the surviving lines exactly where they were. If you also want the result sorted, sort it separately afterwards.
- Are near-duplicates removed too?
- Only exact line matches are treated as duplicates. Lines that differ by capitalisation, extra spaces or punctuation are kept as distinct, so tidy the text first if you want those merged.
- Do blank lines get removed?
- Repeated blank lines collapse the same way repeated text does — the first is kept and further identical blanks are dropped.
- Is my list sent to a server?
- No. De-duplication happens entirely in your browser, so nothing you paste is uploaded or saved.