Remove Duplicate Lines

Delete duplicate lines and dedupe lists.

Options

Free online remove duplicate lines tool

This tool takes any list of lines and returns only the unique ones, deleting every repeated line for you. It's perfect for cleaning up email lists, keyword lists, log files, CSV columns, and any text where the same line appears more than once. The first time each line shows up is kept, and the result updates live as you type or paste — nothing ever leaves your browser.

How to remove duplicate lines

  1. Paste or type your lines into the Input lines box.
  2. Watch the Unique lines box fill in with the duplicates removed.
  3. Optionally tick Ignore case or Trim whitespace to catch near-identical lines.
  4. Tick Remove empty lines or Sort result alphabetically to tidy the output further.
  5. Click Copy output to grab the clean list, or Clear to start again.

Handy options for cleaner lists

Ignore case treats Hello and hello as the same line, while still keeping the exact text of the first one. Trim whitespace ignores stray spaces and tabs at the start or end of a line when comparing, so accidental indentation won't hide a duplicate. Combine them with sorting to turn a messy paste into an ordered, duplicate-free list in one step.

Related text tools

Need to flatten text into a single block instead? Try the Remove Line Breaks tool. To measure the length of your cleaned-up text, head over to the Word Counter. Everything runs privately in your browser, with no sign-up and no limits.

Frequently asked questions

How do I remove duplicate lines from my text?

Paste or type your lines into the input box on the left. The tool instantly removes repeated lines and shows the unique lines in the output box on the right. It keeps the first time each line appears and drops every later copy.

Does it keep the original order of my lines?

Yes. By default the unique lines stay in their original order, and the first occurrence of each line is the one that is kept. If you prefer, tick "Sort result alphabetically" to reorder the output from A to Z instead.

What do the "Ignore case" and "Trim whitespace" options do?

"Ignore case" treats lines like "Apple" and "apple" as the same line when checking for duplicates, while still keeping the first version exactly as you typed it. "Trim whitespace" ignores leading and trailing spaces when comparing, so " hello" and "hello " count as duplicates.

Can it also remove blank lines?

Yes. Tick "Remove empty lines" to strip out any blank or whitespace-only lines from the result, which is handy when cleaning up pasted lists.

Is my text uploaded to a server?

No. Everything runs locally in your browser with JavaScript. Your text is never sent, stored, or shared, so it is safe to deduplicate private or sensitive lists.

Is there a limit on how many lines I can paste?

There is no fixed limit. Because the processing happens on your own device, you can paste very long lists, although extremely large inputs may run a little slower on older hardware.