Random opacity plugin for Illustrator

Randomize Opacity in Adobe Illustrator

Apply a random opacity to each object in a selection from a minimum and maximum value. Compatible with all types of objects within Illustrator.


Randomizing opacity is  a great way to give your patterns and background textures that extra bit of variety to make them non-repetitive. It’s also a great tool for layering shapes and objects on top of each other to create interesting overlap effects. Randomizing opacity works well when combined with the random blend mode feature. A step-size field allows for even more granular control over the generated opacity values.

illustrator random opacity script

Opacity Interface Guide

1. Minimum Opacity

This is the bottom end of the opacity range. Random values generated for opacity will never go below this value. This value must be an integer between 0 and 100. Other values will be auto-corrected to fall within this range.

2. Maximum Opacity

This is the top end of the opacity range. Random values generated for opacity will never go above this value. This value must be an integer between 0 and 100. Other values will be auto-corrected to fall within this range.

3. Step Size

Random opacity values will be generated in increments of this step size value. In this case, the values could be any integer between 1 and 100. If the step size was 50, the only possible generated values would be 0, 50, or 100.

See Randomill's random opacity illustrator script in action:


See how to dial in a minimum, maximum, and step size value to randomize opacity across a group of rectangles while making a cool overlapping square design.