NOPPAW

Remove Duplicate Lines

Remove Duplicate Lines cleans pasted lists the way you wish every app did: repeats are deleted, the first occurrence of each line survives, and the original order is preserved. It is built for the everyday messes — merged spreadsheets, collected email addresses, log excerpts, keyword lists — where the same line sneaks in five times. Matching can be case-sensitive or relaxed, and stray surrounding spaces can be ignored.

0 characters · 0 words · 0 lines

How to use Remove Duplicate Lines

  1. Paste your list into the box, one item per line.
  2. Choose whether matching should be case-sensitive; surrounding spaces are ignored by default.
  3. The deduplicated list appears live — copy or download it.

Supported behavior

  • The first occurrence of each line is kept, with its original text and position.
  • With case-sensitive matching off, 'Apple' and 'apple' count as the same line.
  • Blank lines are treated as a line too: several blank lines collapse into one.

Best for

  • Merging email or username lists from several sources.
  • Cleaning keyword, SKU and inventory lists.
  • Trimming repeated log lines before analysis.

Limits

  • Lines that differ by internal spacing ('a b' vs 'a b') are different lines — run Remove Extra Spaces first if you need those merged.
  • The tool removes exact duplicates only; near-duplicates with typos survive.

Privacy notes

  • Processing happens entirely in your browser, so nothing you paste here is sent anywhere.
  • Lists you paste — emails included — are processed only on your device.

Related tools

Clean & Transform Sort Lines Sort any list of lines six different ways, instantly. Clean & Transform Remove Extra Spaces Collapse double spaces and tidy messy pasted text. Counter Keyword Density Checker Find the density of 1-, 2- and 3-word phrases in your text. Clean & Transform Find and Replace Replace every occurrence of a word or phrase at once.

Remove Duplicate Lines FAQ

Does it keep the first or last occurrence?

The first. Its exact text and position survive; later copies are dropped. That keeps the output order identical to your input order.

What does case-sensitive matching change?

With it on, 'Apple' and 'apple' are different lines and both survive. With it off, they count as one line and only the first spelling is kept.

Can I dedupe a list of thousands of lines?

Yes. The comparison is a fast set lookup, so even very long lists update as you type.