Text Tools

Duplicate Line Remover

Remove duplicate lines from any text with case-sensitive or case-insensitive matching. Optionally remove blank lines and sort the output — copy the result instantly.

Case-Sensitive & Insensitive
Remove Blank Lines
Sort Output
Copy Instantly
Browser-only

Input lines

1 lines

Options

Case-sensitive matching

Remove blank lines

Sort order

Paste lines and click Remove Duplicates

Removing duplicate lines

Duplicate records often appear in exports, word lists, logs, and configuration files. This tool keeps the first occurrence of each line, optionally ignoring letter case and blank lines.

Processing choices

Case-sensitive mode treats Apple and apple as different.
Case-insensitive mode compares normalized lowercase keys.
Sorting runs after deduplication.
Output remains one line per record.

const unique = [...new Set(text.split("\n"))].join("\n");

unique = list(dict.fromkeys(text.splitlines()))

Sort only when order is not meaningful; log files and priority lists often need their original order preserved.

Frequently Asked Questions

What counts as a duplicate line?: By default, two lines are considered duplicates if they are exactly identical (case-sensitive). The tool keeps the first occurrence and removes all subsequent copies.
Is comparison case-sensitive?: You can choose: with case-sensitive mode enabled, 'Hello' and 'hello' are treated as different lines. With case-insensitive mode, they are treated as duplicates and only the first occurrence is kept.
Does the tool preserve blank lines?: By default blank lines are preserved. You can optionally remove all blank lines at the same time as removing duplicates, producing a clean compact output.
What is the maximum text size?: The tool processes text entirely in your browser. Practical limits depend on your device memory, but most modern browsers handle several megabytes of text without issue.
Can I sort lines after removing duplicates?: Yes. The tool includes an optional sort step - apply it after deduplication to produce a sorted, unique list of lines, useful for generating clean word lists or sorted configuration values.

Disclaimer

This tool is provided for general informational and utility purposes only. Results may be inaccurate, incomplete, outdated, or contain errors. Always verify results before relying on or using them.

Some tools may use AI, automated processing, third-party services, or server-side processing. Do not rely on these tools as a substitute for professional advice.

Use at your own risk. BestToolOnline makes no guarantees regarding the accuracy, reliability, completeness, availability, or suitability of results, to the maximum extent permitted by applicable law.

See our Terms of Service and Privacy Policy for complete details.

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Removing duplicate lines

Duplicate records often appear in exports, word lists, logs, and configuration files. This tool keeps the first occurrence of each line, optionally ignoring letter case and blank lines.

Processing choices

Case-sensitive mode treats Apple and apple as different.

Case-insensitive mode compares normalized lowercase keys.

Sorting runs after deduplication.

Output remains one line per record.

const unique = [...new Set(text.split("\n"))].join("\n");

unique = list(dict.fromkeys(text.splitlines()))

Sort only when order is not meaningful; log files and priority lists often need their original order preserved.

Frequently Asked Questions

What counts as a duplicate line?

By default, two lines are considered duplicates if they are exactly identical (case-sensitive). The tool keeps the first occurrence and removes all subsequent copies.

Is comparison case-sensitive?

You can choose: with case-sensitive mode enabled, 'Hello' and 'hello' are treated as different lines. With case-insensitive mode, they are treated as duplicates and only the first occurrence is kept.

Does the tool preserve blank lines?

By default blank lines are preserved. You can optionally remove all blank lines at the same time as removing duplicates, producing a clean compact output.

What is the maximum text size?

The tool processes text entirely in your browser. Practical limits depend on your device memory, but most modern browsers handle several megabytes of text without issue.

Can I sort lines after removing duplicates?

Yes. The tool includes an optional sort step - apply it after deduplication to produce a sorted, unique list of lines, useful for generating clean word lists or sorted configuration values.

Disclaimer

Some tools may use AI, automated processing, third-party services, or server-side processing. Do not rely on these tools as a substitute for professional advice.