THE USEFUL PART / AT A GLANCE
- Give each effect a purpose.
- Pause decorative work when it is not visible.
- Provide a usable reduced-motion experience.
Choose the role of motion
Motion can show a relationship, guide attention or reinforce a visual identity. Decide which of those jobs an effect performs before adding it. A subtle transition that clarifies a state change can contribute more than several competing animated backgrounds.
Keep reading areas calm. When an article, form or service description is the focus, the surrounding visual should support the content rather than continuously demand attention.
Limit work that nobody can see
Decorative canvas and 3D scenes can keep consuming resources even after the user has scrolled away. Use visibility information to start and stop their rendering, and pause them when the browser tab is hidden.
The Intersection Observer API provides a way to observe an element’s intersection with a viewport or another ancestor. In an animation system, that signal can be used to manage the lifetime of decorative effects rather than repeatedly checking layout on every scroll event.
Keep layouts stable
Images, canvases and other media should have sensible dimensions before they finish loading. Stable containers help prevent content and buttons from moving while the page is being read.
Choose effects that fit the available space. A visual that is attractive in a wide desktop layout may need a different composition on a phone. Reducing the number of particles or replacing a large scene with a lighter illustration can preserve the idea without forcing the same treatment everywhere.
Respect different ways of browsing
Reduced-motion preferences should lead to a coherent static or restrained presentation. The content, controls and hierarchy still need to make sense when decorative animation is absent.
Review the page on narrower and shorter screens, with keyboard navigation and with slower media loading. The goal is an experience that remains useful across those conditions, not only a single impressive screenshot.
