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Tool Factory

Text & Lists

Unique Line Filter

Remove repeated lines and keep unique text items.

Tool workspace

Your input stays in this browser.

Add the required input to continue.

Needs input

You can run the tool again after any change.

List options

Split input with

Your result appears here

Remove repeated lines and keep unique text items.

This tool runs open-source code from OmniTools (MIT License). See open-source credits.

Unique Line Filter removes repeated items from a separated list. Choose line breaks for a list with one item per line. Match letter case determines whether apple and Apple remain separate values.

The result contains retained items in first-occurrence order. With Match letter case off, the tool normalizes output to lowercase.

  • Remove repeated identifiers while preserving the first occurrence of each value.
  • Clean repeated lines copied from a log or export.
  • Find items that appear exactly once with Keep items that occur once.

Instructions

  1. Enter one item on each line and choose symbol under Split input with.
  2. Type \n in Split separator and Output separator to use a line break for this example.
  3. Enable Match letter case. Keep Keep items that occur once off to retain one copy of repeated values.
  4. Check Trim items and Discard blank entries before processing rows that contain spaces or blank values.

Example

Input: pear apple pear Apple apple

Settings: Unique Line Filter: split and join on line breaks; Match letter case on; Trim items on; Keep items that occur once off.

Result: pear apple Apple Processing runs in your browser.

Unique Line Filter keeps Apple separately when Match letter case is on. Turning it off produces pear and apple.

Limits

  • Match letter case off merges values with different capitalization and returns lowercase items.
  • Trim items removes surrounding spaces. Keep items that occur once removes every copy of a repeated item.
  • Separators define item boundaries. The tool does not interpret quoted CSV records or nested data.

Questions

What is the difference between distinct and absolutely unique list items?

Distinct output keeps one entry for each value. Absolutely unique output removes every value that occurs more than once, rather than keeping one copy.

Why do my unique list items become lowercase?

Case-insensitive matching uses lowercase keys for the result. Enable case-sensitive matching when the original case distinctions matter.

Do spaces affect duplicate detection?

They can. Enable trimming to remove surrounding spaces before comparison, and choose whether empty items should remain in the input set.