fadeinout

Fadeinout is a term used to describe the gradual change in visibility or loudness of a signal, element, or scene, typically as it appears or disappears from view. In practice, fadeinout encompasses both fading in (increasing opacity or volume from zero) and fading out (decreasing opacity or volume to zero). The concept is widely used across media, software interfaces, and audio production to provide smooth transitions and to signal changes in state or timing.

In audiovisual contexts, fades serve as transitions between scenes or clips. A fade-in gradually reveals an image or video from darkness or a blank canvas, while a fade-out gradually obscures it toward darkness or silence. In audio, fades shape the envelope of a sound, helping to avoid abrupt starts or stops. In user interfaces, fadeinout effects reveal or conceal controls, panels, or messages to guide user attention without jarring disruption.

Common parameters include duration (how long the transition lasts), delay (when it starts), starting and ending levels (often opacity from 0 to 1 or volume from 0 to 100%), and easing (the rate of change over time, such as linear or ease-in/out). Variants include crossfades (simultaneous fades between two sources), fade-to-black or fade-to-white sequences, and text fades.

Implementation methods vary by domain: CSS transitions or animations for web elements, JavaScript or tween libraries for dynamic UI changes, video editing software for scene transitions, and audio plugins or DAWs for gain envelopes. Accessibility considerations include respecting reduced-motion preferences and providing non-visual cues where appropriate.