CSS mask-size Property
Specifies the size of the mask layer image
Syntax
mask-size: auto | <length> | <percentage> | cover | contain;Values
| Value | Description |
|---|---|
| auto | Natural size (default) |
| cover | Covers the entire area |
| contain | Fits within the area |
| 100% 100% | Stretches to fill |
Example
.full-mask {
mask-size: cover;
mask-position: center;
}Understanding CSS mask-size
The CSS mask-size property specifies the size of the mask layer image. As part of the Mask module in CSS, it is one of the most commonly used properties for controlling the visual presentation of web pages.
You can set mask-size to values such as auto, cover, contain, 100% 100%, among others. Each value changes how the browser renders the affected element, giving you fine-grained control over your page layout and design. Choosing the right value depends on the specific design requirements of your project.
Common use cases for the mask-size property include responsive web design, component-based layouts, and creating visually consistent interfaces across devices. It works closely with related properties like mask, mask-image, mask-repeat to achieve complex styling effects. Understanding how these properties interact helps you write cleaner, more maintainable stylesheets.
Browser support for mask-size is excellent across all modern browsers including Chrome, Firefox, Safari, and Edge. For older browsers, consider using fallback values or progressive enhancement strategies. The property can also be set dynamically via JavaScript using element.style.maskSize or the CSS custom properties (variables) approach for theming.
Related Properties
Explore More CSS Properties
Browse our complete reference of 251 CSS properties with syntax, examples, and tips.