Duplicate
World's simplest browser-based utility for duplicating list items. Input your list and specify duplication criteria to create copies of items. Perfect for data expansion, testing, or creating repeated patterns.
Input List
Duplicated List
Tool options
Split Options
Split by Symbol
Split by Regular Expression
Separator to split the list
Separator to join the duplicated list
Duplication Options
Number of copies (can be fractional)
Concatenate copies (if unchecked, items will be interweaved)
Reverse the duplicated items
List Duplication
This tool allows you to duplicate items in a list. You can specify the number of copies (including fractional values), control whether items are concatenated or interweaved, and even reverse the duplicated items. It's useful for creating repeated patterns, generating test data, or expanding lists with predictable content.
Duplicate Examples
Click to try!
Simple duplication
This example shows how to duplicate a list of words.
Split Options
Split by Symbol
Split by Regular Expression
Separator to split the list
Separator to join the duplicated list
Duplication Options
Number of copies (can be fractional)
Concatenate copies (if unchecked, items will be interweaved)
Reverse the duplicated items
Reverse duplication
This example shows how to duplicate a list in reverse order.
Split Options
Split by Symbol
Split by Regular Expression
Separator to split the list
Separator to join the duplicated list
Duplication Options
Number of copies (can be fractional)
Concatenate copies (if unchecked, items will be interweaved)
Reverse the duplicated items
Interweaving items
This example shows how to interweave items instead of concatenating them.
Split Options
Split by Symbol
Split by Regular Expression
Separator to split the list
Separator to join the duplicated list
Duplication Options
Number of copies (can be fractional)
Concatenate copies (if unchecked, items will be interweaved)
Reverse the duplicated items
Fractional duplication
This example shows how to duplicate a list with a fractional number of copies.
Split Options
Split by Symbol
Split by Regular Expression
Separator to split the list
Separator to join the duplicated list
Duplication Options
Number of copies (can be fractional)
Concatenate copies (if unchecked, items will be interweaved)
Reverse the duplicated items
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