Easy Tutorial
❮ Prop Number Type Prop Style Backfacevisibility ❯

HTML Canvas globalAlpha Property

Canvas Object

Example

First, draw a red rectangle, then set the transparency (globalAlpha) to 0.5, and then draw a blue and a green rectangle:

JavaScript:


Browser Support

Internet Explorer 9, Firefox, Opera, Chrome, and Safari support the globalAlpha property.

Note: Internet Explorer 8 and earlier versions do not support the <canvas> element.


Definition and Usage

The globalAlpha property sets or returns the current transparency value (alpha or transparency) of the drawing.

The globalAlpha property value must be a number between 0.0 (fully transparent) and 1.0 (opaque).

Default value: 1.0
JavaScript syntax: context.globalAlpha = number;
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Property Values

Value Description
number The transparency value. Must be between 0.0 (fully transparent) and 1.0 (opaque).

Canvas Object

❮ Prop Number Type Prop Style Backfacevisibility ❯