How is this different from the string category's Line Number Adder?

Line Number Adder only works on newline-separated text. List Item Counter Adder accepts a configurable separator, so it can number a comma-separated list or a list split on a custom delimiter, not just one item per line.

Can I change what appears between the number and the item?

Yes, the counter separator is configurable and defaults to ". " (producing "1. ", "2. ", etc.); change it to ") " for "1) " style numbering, ": " for "1: " style, or anything else you prefer.

Does numbering restart if I run it twice?

Running it a second time on already-numbered output will add a second numeric prefix in front of the first, since the tool doesn't detect existing numbering. Use List Item Counter Remover first if you need to strip old numbers before renumbering.

List Item Counter Adder - Number Every List Item

Overview

Introduction

Numbered lists are easier to reference and discuss than plain unordered text, but adding numbers by hand to a long list is tedious.

This tool prefixes every item in a list with its position number, using whatever separator style you choose.

What Is List Item Counter Adder?

A list transformer that adds a 1-based index prefix to every item, in a format you control via a configurable counter separator string.

Unlike the string category's newline-only Line Number Adder, this tool works with newline, comma, or custom-delimited lists.

How List Item Counter Adder Works

The list is split into items using the resolved separator, and each item is prefixed with its 1-based index followed by the counter separator string (default ". ").

The numbered items are then rejoined using the same list separator to produce the final output.

When To Use List Item Counter Adder

Use it to turn a plain list into a numbered list for documentation, instructions, or a step-by-step guide.

It's also useful for adding reference numbers to a list before discussing or editing specific entries by number.

Often used alongside List Item Counter Remover, List Item Bullet Adder and Line Number Adder.

Features

Advantages

Fully configurable numbering format via the counter separator string.
Works with any of the supported list separator modes, not just newline.
Fast, deterministic numbering with no manual counting required.

Limitations

Does not detect or skip existing numbering; running it twice stacks a second number in front of the first.
Always starts counting at 1; there is no option to start from a different number.
Only supports simple sequential numeric prefixes, not roman numerals or lettered lists.

Examples

Default numbering

Input

apple
banana
cherry

Output

1. apple
2. banana
3. cherry

Each item is prefixed with its 1-based index and the default ". " separator.

Custom counter separator

Input

step one
step two (separator: ") ")

Output

1) step one
2) step two

Changing the counter separator to ") " produces "1) " style numbering.

Best Practices & Notes

Best Practices

Run List Item Counter Remover first if your list may already contain leftover numbering, to avoid double-numbering.
Sort or reorder your list first with List Sorter or List Reverser before numbering, since numbers are assigned based on final position.
Pick a counter separator that matches your target document's style, for example ") " for outline-style numbering.

Developer Notes

Implemented with `Array.prototype.map()` over the split item array, building each output entry as a template string `${index + 1}${counterSeparator}${item}` before rejoining with the shared `joinListItems()` helper.

List Item Counter Adder Use Cases

Turning a plain list into numbered step-by-step instructions
Adding reference numbers to a list for discussion or editing
Preparing a numbered list for import into another document format

Common Mistakes

Running the tool twice on already-numbered output, which stacks a second numeric prefix rather than replacing the first.
Expecting the numbering to restart at a custom value; it always begins at 1.
Forgetting to reorder the list first, since numbering reflects the list's current order, not any intended future order.

Tips

Use List Item Counter Remover afterward if you decide you want the plain, unnumbered list back.
Chain with List Sorter first if the numbered order needs to reflect an alphabetical or numeric sort.

List Item Counter Adder