Remove Duplicate Lines

Order

The first occurrence of each exact line is kept. Comparison is case-sensitive.

Developer Quick Tips

• Paste a list and press Ctrl or Cmd + Enter to remove duplicate lines instantly in your browser.
• Preserves original order and first occurrence, unlike 'sort -u' on Linux; similar to 'uniq' command.
• Use before importing lists into databases, logs, config files, or APIs to clean exact duplicates.
• Comparison is case-sensitive: apple and Apple are treated as different lines.
• Combine with Trim Lines for whitespace normalization, or Sort Lines after for alphabetical order.

Frequently asked questions

How do I remove duplicate lines online?

Paste your list into this tool and press Ctrl or Cmd + Enter. It deduplicates instantly in your browser without uploading or requiring an account. Works on any plain text list.

How do I remove duplicate lines in Excel?

Excel has a built-in Remove Duplicates feature, but this tool runs entirely in your browser on plain text lists. Paste any list and deduplicate locally without uploading or leaving your device.

How do I remove duplicate lines on Linux?

Use 'uniq' to preserve order or 'sort -u' to sort first. This tool does the same as 'uniq' but in your browser without opening a terminal. Paste your list and deduplicate instantly for quick one-off tasks.

How do I remove duplicate lines in Vim?

In Vim, use ':sort u' or filter through 'uniq'. This tool offers the same result in your browser. Paste your list, deduplicate, and copy the output back into your editor.

Is the comparison case-sensitive?

Yes. apple and Apple are treated as different lines. Only exact matches are removed. If you need case-insensitive deduplication, normalize case first using another tool.

What does 'dedupe' mean?

Dedupe (short for deduplicate) means removing duplicate entries while keeping unique ones. This tool removes duplicate lines while preserving the first occurrence of each exact line in original order.

Does Remove Duplicate Lines upload my data?

No. Remove Duplicate Lines runs locally in your browser. Your input is not uploaded to our servers for processing.

Will my input be stored after I close the tab?

No. Input stays in memory for the current page. Closing the tab clears it. Theme preference is stored locally in your browser and is not tool input.

Related tools

• Sort Lines: Order and sort lines alphabetically online with numeric-aware, case-insensitive comparison. Free browser tool, no upload, no account needed.
• Trim Lines: Trim leading and trailing whitespace from each line locally. Preserves inner spaces and blank lines. Free, browser-based, no upload.