Free Remove Duplicate Lines Tool Online

Clean Up Any List in Seconds

Lists grow messy quickly. Merge two contact sheets and the same email appears twice; collect keywords from different tools and dozens repeat; export URLs from a website crawl and find the same page listed again and again. This tool removes duplicate lines from any list, can drop empty lines and stray spaces, and tells you exactly how many lines were removed.

How to Use the Tool

Paste your list into the box, one item per line.
Choose your filter settings:
- Case Sensitive — treat “India” and “india” as different lines.
- Remove Empty Lines — delete blank lines.
- Trim Whitespace — ignore spaces at the start and end of each line.
Click Remove Duplicates.
Check the Cleaning Report for original lines, lines removed and unique lines kept. Then copy the result or download it as a .txt file.

Example

Input (with Case Sensitive off and Trim Whitespace on):

apple
Banana
apple
banana

cherry

Output:

apple
Banana
cherry

The second “apple” and the “ banana” with a leading space are removed as duplicates, and the blank line is dropped. Six lines become three.

Choosing the Right Settings

Type of list	Case Sensitive	Trim Whitespace
Email addresses	Off	On
SEO keywords	Off	On
URLs	On (paths can be case-sensitive)	On
Product codes / SKUs	Depends on your system	On
Code or passwords	On	Off

Common Uses

Marketing: deduplicating email or phone lists before a campaign, so nobody gets the same message twice.
SEO: merging keyword lists from several research tools into one clean list.
Web development: cleaning lists of URLs, redirects or log entries.
Data entry: tidying up a column copied from Excel or Google Sheets before pasting it back.
Teachers and students: removing repeated names from attendance or registration lists.

Doing It in Excel vs Using This Tool

Spreadsheets can remove duplicates too (Data → Remove Duplicates in Excel), but they don’t trim hidden spaces automatically and can be awkward for quick one-off lists. This tool is faster for plain text: paste, click, copy. For structured data with several columns, a spreadsheet is still the better choice.

Related Tools

Case Converter — make every line lowercase before deduplicating.
Word Counter — count words and lines.
CSV to JSON — convert cleaned lists into JSON for developers.

Frequently Asked Questions

It reads your text line by line and keeps only the first time each line appears, removing any later repeats. The original order of the remaining lines is preserved.

When it is on, "Apple" and "apple" are treated as different lines and both are kept. When it is off, they are treated as the same, and only the first one is kept.

Lines copied from spreadsheets or websites often have invisible spaces at the start or end. Without trimming, "hello" and "hello " look identical but are treated as different. Trimming removes those spaces before comparing.

Yes. Paste one email per line, turn Case Sensitive off (email addresses are not case-sensitive in practice) and keep Trim Whitespace on. The result is a clean list of unique addresses.

There is no fixed limit. Because processing happens in your browser, tens of thousands of lines work smoothly on most computers; very large files may be slower on older phones.

No. The list is processed entirely in your browser, so customer lists and private data never leave your device.

Remove Duplicate Lines

Process List

Cleaning Report