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Remove duplicate lines from text

Remove Duplicates scans the pasted text line by line and keeps only the first occurrence of each, so repeated lines disappear while everything else keeps its original order. Developers use it to compress repetitive log output and dedupe option lists, and organisers trim pasted guest lists or CSV extracts before an import. Matching is exact by default: Error and error are different lines, and a trailing space makes a line unique. Tick "Ignore case" to treat them as the same.

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How to use Remove Duplicates

  1. Open Remove Duplicates in the Toolbox101 app.
  2. Paste the list or log excerpt into the Lines box. Every line is compared with the ones above it.
  3. Tick Ignore case if Apple and apple should count as the same line.
  4. Read the result in the Output box; the first occurrence of each line stays where it was. Click Copy to take it.

Worked example

Remove Duplicates returns the output below for this input.

Input

apple
banana
apple
cherry
banana

Output

apple
banana
cherry

Check it yourself: open Remove Duplicates and enter the same input.

Frequently asked questions

Does it keep the first or the last occurrence of a duplicate?

The first. Each line is kept the moment it is seen, and later identical lines are skipped, so the result preserves the order of first appearances: duplicates later in the text never shift earlier lines. That matters when your lines carry timestamps or sequence meaning.

Is duplicate detection case-sensitive?

By default yes, and whitespace-sensitive too: Error and error are both kept, and apple with a trailing space differs from apple. Tick Ignore case to treat them as one; the first spelling is the one kept. To ignore padding, run Strip Whitespace with Trim each line first.

Will it dedupe words inside a single line?

No. The tool works on whole lines only: a line is removed only when an identical previous line exists. Repeated words within one line, or comma-separated values sharing a line, are left untouched. If your data is one value per line, paste it as-is.

Use Remove Duplicates now

Open Remove Duplicates in the app

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