Remove Duplicate Lines

Remove duplicate lines from a list, with options to ignore case, trim spaces and drop empty lines.

Paste a list, get it back with the repeats removed. The original order is preserved and everything happens in your browser.

  • 0Lines in
  • 0Lines out
  • 0Removed

How Does It Work?

  1. Paste your listOne item per line. Emails, URLs, product codes, names — anything.
  2. Choose how strict to beTrimming spaces and ignoring case catch near-duplicates that look identical to a human but differ byte for byte.
  3. Copy the clean listThe first occurrence of each line is kept and the original order is preserved.

What Is It Used For?

Merged exports, copied spreadsheets and combined mailing lists nearly always carry duplicates, and the differences are often invisible — a trailing space, a capital letter. Deduplicating in the browser avoids uploading a list of customer emails to an unknown website just to clean it.

  • Cleaning a mailing list built from several sources.
  • Removing repeated rows from a pasted export before importing it.
  • Tidying a list of URLs, keywords or tags.
  • Finding out which entries actually repeat, using the duplicates-only mode.
  • Producing a unique set of IDs or codes for a script.

Examples

InputOptionsResult
apple, banana, appleDefaultapple, banana
Apple, appleDefaultApple, apple (both kept)
Apple, appleIgnore caseApple
" apple", "apple"Trim spacesapple
apple, banana, appleShow duplicates insteadapple

Frequently Asked Questions

Does it keep the original order?

Yes. The first occurrence of each line stays where it was, and later repeats are removed. Turn on "Sort result" if you would rather have it alphabetical.

Are "Apple" and "apple" the same line?

Only if you turn on "Ignore case". By default the comparison is exact, so different capitalisation counts as two different lines.

What does trimming spaces do?

It removes leading and trailing whitespace before comparing, so " apple" and "apple" are treated as the same entry. The trimmed version is what appears in the result.

Can I see which lines were duplicated?

Yes — switch on "Show duplicates instead" and the output lists only the entries that appeared more than once.

Is my list uploaded to a server?

No. Everything runs locally in your browser, which matters when the list contains customer data or email addresses.

Free. No registration. This tool runs entirely in your browser, so the data you enter stays on your device.

Sort Lines Alphabetically

Sort any list A–Z, Z–A, by number or by length.

Line Counter

Count total, non-empty, unique and duplicate lines in a list.

Word Counter

Count words, characters, sentences and paragraphs as you type.

Uppercase / Lowercase Converter

Change text to UPPERCASE, lowercase, Title Case and more.