How to remove duplicate lines
- Paste or type your list into the top box — one item per line (emails, keywords, URLs, log lines, or a column copied from a spreadsheet).
- Choose your options: ignore case, trim spaces before comparing, or also drop blank lines — then pick whether to keep the first copy or only the never-repeated lines.
- The clean list appears instantly below. Click Copy or Download .txt to save it.
Clean up any list while keeping its order
Duplicates creep into lists all the time — you merge two email exports, paste keyword research from several tools, or concatenate log files, and suddenly the same value appears again and again. Removing them by hand is slow and easy to get wrong. This tool scans every line and strips the repeats in a single pass, so a list of thousands of rows is de-duplicated the moment you stop typing. Crucially, it preserves the original order. Many people reach for a spreadsheet or a sort command to remove duplicates, but sorting reshuffles everything — which destroys meaningful sequences like chronological logs, a hand-ranked priority list, or CSV rows that need to line up with another column. Here, the first time a line appears is exactly where it stays.
Trim, ignore case, and choose how strict to be
Real lists are rarely perfectly clean. A trailing space, a stray tab, or one capital letter can make two lines that look identical count as different. Turn on Trim whitespace before comparing (on by default) so apple and apple match, and Case-insensitive so Apple and apple match. You still get the original text in the output — the options only change how lines are compared, not how they are written back. Two keep-modes control how aggressive the cleanup is. Keep first occurrence is the classic dedupe: every distinct line survives once and the extra copies vanish. Keep only unique lines is stricter and great for finding the odd one out — it drops every line that shows up more than once, leaving only the values that appeared a single time, which is perfect for spotting entries present in one list but not another. Everything runs locally in your browser, so even sensitive lists like customer emails never leave your device, and there is no upload and no size cap.
Frequently asked questions
Does it keep the original line order?
Yes. Lines stay in the exact order you pasted them — only later duplicates are removed. This is the main difference from a sort-and-dedupe approach, which reshuffles everything.
Can it ignore uppercase and lowercase?
Yes. Turn on Case-insensitive and lines like Apple and apple are treated as the same, so only the first one is kept.
What is the difference between the two keep modes?
Keep first occurrence keeps one copy of every line and drops the repeats. Keep only unique lines is stricter — it removes every line that appears more than once, so only lines that were never repeated remain.
Is my text uploaded to a server?
No. Everything runs locally in your browser with JavaScript. Your text never leaves your device.
Is there a size limit?
No fixed limit. You can paste thousands of lines; the tool processes them instantly in memory on your own machine.