How does duplicate detection work?

Each line is compared to all previously seen lines. The first occurrence is kept and any subsequent identical lines are dropped. The relative order of unique lines is preserved by default.

What does case-insensitive matching do?

'Hello' and 'hello' would normally be treated as different lines. With case-insensitive matching enabled, they are considered duplicates and only the first occurrence is kept.

What does trim whitespace do?

Leading and trailing spaces are stripped from each line before comparison. This means ' hello ' and 'hello' are treated as the same line.

Does sorting affect which duplicate is kept?

Sorting reorders the final output alphabetically but does not affect which line is kept — duplicates are still removed in the original top-to-bottom order before sorting.

Private by defaultRuns in your browser

Duplicate line remover

Paste your text and get back only unique lines. Useful for cleaning up lists, log output, CSV data, and any text with repeated entries.

InputOne item per line

Unique lines

Case-sensitiveTrim whitespaceSort output

Quick samplesUseful for testing

Duplicate Remover

About this tool

Paste text to remove repeated lines and copy clean unique output. Case-insensitive matching, trim whitespace, sort — instant, browser-based.

Paste your text and get back only unique lines. Useful for cleaning up lists, log output, CSV data, and any text with repeated entries.

No signup requiredRuns in your browserInstant results

How to use

1
Paste your list or text with duplicate lines into the input field.
2
Choose whether to keep the first or last occurrence of each duplicate.
3
Optionally sort the result after deduplication.
4
Click Copy to copy the cleaned list.

Why use this tool?

→
Clean up exported lists or CSVs that contain repeated rows before importing.
→
Deduplicate log output or error messages to focus on distinct events.
→
Remove repeated entries from a manually assembled list of IDs, emails, or URLs.

ExamplesInput → output

Remove duplicate lines

Input

apple
banana
apple
orange
banana

Output

apple
banana
orange

Deduplicate a comma list

Inputa, b, a, c, b, d

Outputa, b, c, d

Frequently asked questionsCommon questions answered

These answers explain common duplicate remover tasks, expected input formats, and edge cases so both visitors and search engines can understand what this tool does.

How does duplicate detection work?: Each line is compared to all previously seen lines. The first occurrence is kept and any subsequent identical lines are dropped. The relative order of unique lines is preserved by default.
What does case-insensitive matching do?: 'Hello' and 'hello' would normally be treated as different lines. With case-insensitive matching enabled, they are considered duplicates and only the first occurrence is kept.
What does trim whitespace do?: Leading and trailing spaces are stripped from each line before comparison. This means ' hello ' and 'hello' are treated as the same line.
Does sorting affect which duplicate is kept?: Sorting reorders the final output alphabetically but does not affect which line is kept — duplicates are still removed in the original top-to-bottom order before sorting.