Remove Duplicate Lines

Free tool to remove duplicate lines from a list. Dedupe, trim, sort and clean any list with case-insensitive and blank-line options — instantly and privately in your browser.

✓ Free ⚡ Instant 🔒 100% private
Your list0 lines
Result0 lines
Paste a list above to remove duplicate lines.

🔒 Everything runs in your browser — your list is never uploaded.

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Free Remove Duplicate Lines Tool

This free online tool helps you remove duplicate lines from any list in seconds. Paste your text on the left and a clean, deduplicated version appears instantly on the right. You can ignore letter case, trim spaces, skip blank lines, sort the result alphabetically, or flip it around to keep only the duplicates. It’s free, needs no sign-up, and runs entirely in your browser.

How to use this tool

  1. Paste your list into the box on the left, one item per line (or click Load sample).
  2. The deduplicated result appears on the right and updates live as you type.
  3. Tick the options you need — case-insensitive, trim whitespace, ignore or remove blank lines, or sort A–Z.
  4. Use Keep only duplicates if you instead want to see which lines were repeated.
  5. Click Copy result to copy the clean list to your clipboard.

When is this useful?

Duplicate lines creep into data more often than you’d think. If you are cleaning email lists before a campaign, removing repeats keeps you from messaging the same person twice and protects your sender reputation. SEO and marketing teams use it to deduplicate keyword lists pulled from several tools, so each term is counted once. Developers and analysts dedupe log files to collapse repeated error lines, or clean up a single CSV column after pasting it out of a spreadsheet.

The stats line tells you exactly what happened — how many lines went in, how many unique lines came out, and how many duplicates were removed — so you can trust the result before you copy it. Because everything runs on your own device, even very large lists are processed instantly and your data never leaves your computer.

Frequently asked questions

Does removing duplicates keep the original order?
Yes. By default the tool keeps the first occurrence of each line in its original position and removes the later repeats. If you prefer an ordered result, tick Sort A–Z to arrange the unique lines alphabetically.
What does case-insensitive matching do?
With Case-insensitive ticked, lines that differ only in letter case are treated as the same. For example Apple, apple and APPLE count as one line, and the first version you typed is kept in the result.
What is the difference between ignoring and removing blank lines?
Ignore blank lines leaves empty lines out of the duplicate check but can still keep a single blank as spacing, while Remove all blank lines strips every empty line from the output completely. Use the second option when you want a tight, gap-free list.
How do I see only the lines that are duplicated?
Tick Keep only duplicates. Instead of returning unique lines, the tool then lists just the entries that appeared more than once, which is handy for finding repeated emails, IDs or keywords in a large list.
Is this tool free and private?
Yes. It is completely free with no sign-up, and all processing happens in your browser with JavaScript. Your list is never uploaded to any server, so it stays private on your own device.
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