Remove Duplicate Lines — Deduplicate Text Online

About This Remove Duplicate Lines Tool

This free online tool removes duplicate lines from any list or block of text. Paste a list of names, emails, phone numbers, IDs, URLs, or any text — the tool keeps only the unique entries and removes every repeated line. It is used by data entry operators, marketers, HR professionals, researchers, and anyone who needs a clean deduplicated list.

What This Tool Can Do

• Remove duplicate lines — every repeated entry is removed
• Case-insensitive option — treat Apple and apple as duplicates
• Trim whitespace — ignore leading/trailing spaces when comparing
• Remove empty lines — skip blank lines in the output
• Keep first or last — decide which occurrence survives
• Sort output — A→Z, Z→A, or keep original order
• Preview result — check before you commit
• Undo — revert the last operation

Common Uses

• Clean email lists before an email campaign
• Remove repeated customer names from a CRM export
• Deduplicate URLs before crawling or scraping
• Clean student roll numbers or employee IDs
• Remove duplicate entries from attendance sheets
• Clean survey responses with repeated answers
• Deduplicate citation lists before submission
• Remove repeat lines from log files

Frequently Asked Questions

What does the Remove Duplicate Lines tool do?

This tool removes duplicate lines from any text or list. Paste a list of names, emails, IDs, URLs, or any text — the tool keeps only the unique lines and removes every repeated entry.

Does it consider case when removing duplicates?

By default, the tool is case-sensitive, so Apple and apple are treated as different. You can enable the Ignore case option to treat them as duplicates.

Can I keep the last occurrence instead of the first?

Yes. The tool lets you choose whether to keep the first or the last occurrence of each duplicate line.

Can it remove duplicate emails or phone numbers?

Yes. Paste one email or phone number per line and the tool will remove every repeated entry, keeping only unique values.

Will the tool preserve the original order of my list?

Yes. By default, the output keeps the original order of the list. You can optionally sort the output A→Z or Z→A using the Sort dropdown.

What happens if two lines differ only by spaces?

By default, the Trim whitespace option is enabled — so "apple " and "apple" are treated as duplicates. Turn it off if you want to keep them separate.

Is this tool free?

Yes. The tool is completely free to use. No signup, no registration, and no download required.

Can I use it on mobile?

Yes. The tool works on mobile phones, tablets, and desktop computers.