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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.

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

Concatenate copies (if unchecked, items will be interweaved)

Reverse

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

Concatenate copies (if unchecked, items will be interweaved)

Reverse

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

Concatenate copies (if unchecked, items will be interweaved)

Reverse

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

Concatenate copies (if unchecked, items will be interweaved)

Reverse

Reverse the duplicated items

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