Remove Duplicate Lines – Clean Your List Instantly
Paste a list and remove duplicate lines in one click. Keep the original order or sort A–Z, ignore case, trim spaces, and drop blank lines. Free, no sign-up, and everything runs in your browser — nothing is stored or uploaded.
This free tool removes duplicate lines from any list in one click, leaving only unique entries. Paste your text, choose a few options if you need them, and copy a clean result. It is built for anyone working with lists — marketers de-duplicating email or keyword lists, developers cleaning log lines or config entries, students tidying references, and anyone merging data from several sources. Instead of scanning line by line or fighting with spreadsheet formulas, you get the unique lines instantly. You can keep the original order or sort the result, ignore case, trim spaces, and drop blank lines. Everything runs in your browser — nothing is uploaded, and your text stays saved locally so it is there when you come back. Paste your list above and click to clean it.
What does this tool do?
It scans your text line by line and keeps only the first (or last) occurrence of each line, removing every repeat. It then shows how many lines went in, how many are unique, and how many duplicates were removed. Options let you control exactly what counts as a duplicate:
- Ignore case — treats "Apple" and "apple" as the same line.
- Trim spaces — ignores leading and trailing spaces when comparing.
- Remove blank lines — drops empty lines from the result.
- Sort A–Z — alphabetizes the unique lines.
- Keep first or last — choose which occurrence of a repeated line to keep.
Why use this tool?
Duplicate entries creep into lists whenever data is copied, merged, or exported from different places. They inflate counts, skew results, and cause errors down the line — a mailing list with repeats wastes sends, a keyword list with duplicates distorts research, and a data import with repeated rows can break a process. Removing them by hand is slow and unreliable, and spreadsheet methods are fiddly. This tool does it instantly and tells you exactly how many duplicates it found.
How the tool works
- Your text is split into lines at each line break.
- If Trim spaces is on, each line's leading and trailing spaces are ignored for comparison.
- Each line is compared against the ones already kept; if it matches (case-sensitively, or case-insensitively when Ignore case is on), it is treated as a duplicate and skipped.
- With Keep last, the tool scans from the bottom up, so the final occurrence is the one kept, then restores the original order.
- If Sort A–Z is on, the unique lines are ordered alphabetically (numbers are compared naturally).
How to use the tool
- Paste or type your list in the left box, one item per line.
- Set the options you need (ignore case, sort, keep first/last…).
- Click Remove duplicates.
- Read the summary to see how many duplicates were removed.
- Click Copy result to grab your clean list.
Practical examples
Email list cleanup
Merge two subscriber lists, turn on Ignore case, and remove repeated addresses so no one is emailed twice.
Keyword research
Paste keywords gathered from several tools and strip duplicates to get a clean, accurate list to work from.
Log or data lines
Developers paste repeated log entries or config lines and keep only the unique ones for review.
Reference list
Students combine sources and remove duplicate citations, then sort A–Z for a tidy bibliography.
Common use cases
- Marketers: de-duplicating email lists, keyword lists, and ad targets.
- Developers & analysts: cleaning log lines, CSV columns, and config entries.
- Students & researchers: tidying references and combined notes.
- Anyone merging data from multiple sources into one clean list.
Tips & best practices
- Turn on Ignore case when the same entry may be typed with different capitalization.
- Keep Trim spaces on for pasted data — stray spaces often hide true duplicates.
- Use Keep last when the most recent version of a line is the one you want.
- Sort A–Z when the order does not matter and you want a list that is easy to scan.
Frequently Asked Questions
Does it keep the original order?
Yes, by default. Unique lines stay in the order they first appear, unless you turn on Sort A–Z.
What counts as a duplicate?
Two lines that match exactly. With Trim spaces on, surrounding spaces are ignored; with Ignore case on, capitalization is ignored too.
What is the difference between keeping the first and last occurrence?
Keep first retains the earliest appearance of a repeated line; keep last retains the final one. The result order is otherwise preserved.
Does it remove duplicate words, or whole lines?
Whole lines. Each line is compared in full, so it is ideal for lists where every item sits on its own line.
Can it also count how many duplicates there were?
Yes. After each run it shows total lines in, unique lines out, and the number of duplicates removed.
Is there a limit on list size?
No fixed limit. It handles short lists and large ones, and processing is instant because it runs in your browser.
Will it change my original text?
No. Your input stays in the left box; the cleaned result appears separately on the right, so you can compare or re-run with different options.
Is my data private?
Yes. Everything runs in your browser. Your list is never uploaded to or stored on a server.
Is the tool free?
Completely free, with no account and no limit on how many lists you clean.