opacity() CSS function

The opacity() CSS function applies transparency to the samples in the input image. Its result is a <filter-function>.

Try it

filter: opacity(1);
filter: opacity(80%);
filter: opacity(50%);
filter: opacity(0.2);
filter: opacity(0);
<section id="default-example">
  <img
    class="transition-all"
    id="example-element"
    src="/shared-assets/images/examples/firefox-logo.svg"
    width="200" />
</section>

Note: This function is similar to the more established opacity property. The difference is that with filters, some browsers provide hardware acceleration for better performance.

Syntax

css
opacity(amount)

Parameters

amount Optional

The amount of the conversion, specified as a <number> or a <percentage>. A value of 0% is completely transparent, while a value of 100% leaves the input unchanged. Values between 0% and 100% are linear multipliers on the effect. The initial value for interpolation is 1. The default value is 1.

Formal syntax

<opacity()> = 
  opacity( [ <number> | <percentage> ]? )

Examples

undefined

Examples of correct values for opacity()

css
opacity(0%)   /* Completely transparent */
opacity(50%)  /* 50% transparent */

opacity()     /* No effect */
opacity(1)

Specifications

See also