How does duplicate detection work?

Each line is compared to all other lines. The first occurrence is kept and subsequent duplicates are removed, preserving the original order.

What does the case-sensitive option do?

When case-sensitive is on, 'Hello' and 'hello' are treated as different lines. When off, they are treated as duplicates.

When enabled, leading and trailing spaces on each line are ignored when comparing for duplicates, so ' hello ' and 'hello' are treated the same.

No. All processing happens locally in your browser. Your text never leaves your device.

Paste your text to remove duplicate lines. Toggle case sensitivity and whitespace trimming.

Case SensitiveTrim Whitespace

Output (duplicates removed)

Deduplicated text will appear here...

Step 1

Paste or type your text with duplicate lines.

Step 2

Toggle case-sensitive and trim whitespace options.

Step 3

View the duplicate count and cleaned output instantly.

Step 4

Click Copy to copy the deduplicated text.

Instant duplicate line detection and removal.

Case-sensitive and case-insensitive matching.

Optional whitespace trimming for flexible comparison.

Shows the number of duplicate lines removed.

Completely free with no sign-up required.

: Each line is compared to all other lines. The first occurrence is kept and subsequent duplicates are removed, preserving the original order.
: When case-sensitive is on, 'Hello' and 'hello' are treated as different lines. When off, they are treated as duplicates.
: When enabled, leading and trailing spaces on each line are ignored when comparing for duplicates, so ' hello ' and 'hello' are treated the same.
: No. All processing happens locally in your browser. Your text never leaves your device.