Remove duplicates in four steps
- Paste your list into the left-hand box of the Duplicate Line Remover, one item per line.
- Choose how lines are compared. The default — case-insensitive, with surrounding spaces ignored — suits most lists.
- Choose whether to keep the first or the last occurrence of each repeated line, and whether to sort the result (A to Z, Z to A, natural number order or shortest first).
- Select Remove duplicates, then copy or download the clean list.
The duplicate report shows which lines appeared more than once and how many times, which is useful for spotting a form that was submitted repeatedly.
Choosing the right comparison
- Email addresses: case-insensitive.
Ali@Example.comandali@example.comreach the same inbox. - Keywords: case-insensitive with spaces trimmed.
- Product codes, passwords, IDs: case-sensitive, because
AB-12andab-12may be different items. - URLs: usually case-sensitive after the domain, since many servers treat
/Pageand/pageas different addresses.
Keep first or keep last?
If your list is in date order and later entries are more up to date (for example, a customer who signed up twice with different details), keep the last occurrence. If the first entry is the original and later ones are accidental repeats, keep the first. When you do not sort, the remaining lines stay in their original order.
Near-duplicates and spreadsheet data
The tool compares whole lines, so “Main St” and “Main Street” are different. Normalise variations first with the Find and Replace Tool, or change everything to one case with the Case Converter.
If you paste several spreadsheet columns, a line counts as a duplicate only when every column matches. To de-duplicate by one column, such as email, copy just that column.
Doing it in Excel or Google Sheets
Spreadsheets can also remove duplicates: in Excel, select the data and use Data → Remove Duplicates; in Google Sheets, Data → Data cleanup → Remove duplicates. An online tool is quicker for lists you have copied from emails, documents or web pages, and it shows a report of what was removed.
Frequently asked questions
Is there a limit on list size?
Lists of hundreds of thousands of lines work well. Lists with several million lines may exceed your browser’s memory.
Are blank lines removed?
Yes, by default. Untick Remove blank lines if you want to keep them; repeated blank lines are then treated like any other duplicate.
Is my list uploaded?
No. The comparison runs in your browser, which makes it safe for customer email lists and other private data.