What does case-insensitive matching do?

When case-insensitive is enabled, 'Hello' and 'hello' are treated as duplicates. The first occurrence is kept with its original casing.

What does 'trim lines before comparing' do?

It strips leading and trailing whitespace from each line before checking for duplicates. Lines that differ only in whitespace are treated as duplicates.

Is the original order preserved?

Yes. The tool keeps the first occurrence of each unique line and removes subsequent duplicates, preserving the original order of lines.

Duplicate Line Remover

Remove duplicate lines while preserving the original order of first occurrences. Case-sensitive and insensitive modes. Optionally trim whitespace before comparing. All processing happens in your browser.

Options

Case-sensitive comparisonTrim lines before comparing

Your files are processed entirely in your browser. Nothing is uploaded to any server.

How to Use Duplicate Line Remover

1
Paste or type your text
Enter your text in the input area. You can paste from clipboard or type directly.
2
See instant results
The tool processes your text automatically as you type. Adjust options if available.
3
Copy the output
Click the copy button to save the result to your clipboard. No data leaves your browser.

Frequently Asked Questions

Next Steps

Sort the remaining lines

Trim whitespace from lines

Related Tools

Sort Lines

Sort alphabetically, numerically, or by length.

Line Counter

Count lines with any line ending format.

Whitespace Remover

Strip extra spaces from every line instantly.

Related Guides

How to Clean and Format Text Online — Practical Guide

A practical guide to common text-cleaning tasks: word count, case conversion, line sorting, whitespace removal, and deduplication.