Storyline 360 now supports transparent WebM video

Hello and welcome to 2026, Storyline users! Toward the end of the last year, we quietly shipped something pretty powerful.

You can now import WebM videos into Storyline, including those that use real alpha channel transparency.

In the clip below, I’m dropping a WebM onto a slide with a textured background so you can clearly see that texture showing through the video. Then on the next slide, I add a few objects that animate behind the video while it’s playing. No boxes. No masking tricks. Just actual transparency doing what it’s supposed to do.

This wasn’t a big splashy launch, but it meaningfully expands what you can create. If you’ve ever wanted motion graphics or visual effects with transparency that feel native to the slide, this opens that door.

One important note: support for transparent WebM is solid in Chrome, Edge, Firefox, and other Chromium-based browsers. Safari and Apple devices don’t currently support WebM transparency in the same way, so this works best when your learners are on those supported browsers.
I’m really curious about how you'll use this.