Apply a Function on a List

This tool lets you transform each item in a list using common string functions like uppercase, lowercase, capitalization, and character reversal. You can also add custom prefixes or suffixes to each line. It processes input instantly with live updates and supports file import, export, and copying.

Paste your input above or import a file below.
No file chosen
Supported file types: .txt, .csv, .tsv, .log, .json, .xml, .md, .ini, .yaml, .yml, .html, .htm, .css
Total items: 0
Options
Trim lines
Ignore empty lines

How to Use:

  1. Paste or import your list into the Input List box.
  2. Choose a transformation under Function (e.g. UPPERCASE, lowercase).
  3. Adjust Options:
    • Trim lines: removes leading/trailing spaces
    • Ignore empty lines: skips blank entries
    • Set a prefix or suffix if desired
  4. The transformed result appears in real time in the Transformed Output box.
  5. Use Copy Output or Export to File to save results.
  6. Click Clear All to reset.

Example:

Input:

apple
banana
CHERRY

Settings:

  • Function: Capitalize
  • Prefix: Fruit:

Output:

Fruit: Apple
Fruit: Banana
Fruit: Cherry

Common Use Cases:

This tool is ideal for formatting lists for presentation, cleaning up data for processing, or applying consistent naming conventions in logs, spreadsheets, and structured exports.

Useful Tools & Suggestions:

If you’re applying a function on a list, Reduce a List is a great next step especially when you want to collapse everything into a single value or summary. And if you’re starting with raw or messy data, Trim List Items can help clean things up before the function runs. This workflow makes it easier to apply logic or math without getting tripped up by bad formatting.

Related Tools