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    <title>DEV Community: Pavel</title>
    <description>The latest articles on DEV Community by Pavel (@devyatov).</description>
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    <item>
      <title>Liquid Glass on the Web: 6 Ways to Build It with CSS and SVG</title>
      <dc:creator>Pavel</dc:creator>
      <pubDate>Tue, 04 Aug 2026 21:16:28 +0000</pubDate>
      <link>https://dev.to/devyatov/liquid-glass-on-the-web-6-ways-to-build-it-with-css-and-svg-3m07</link>
      <guid>https://dev.to/devyatov/liquid-glass-on-the-web-6-ways-to-build-it-with-css-and-svg-3m07</guid>
      <description>&lt;p&gt;Apple shipped Liquid Glass across iOS 26 and macOS, and suddenly every product I look at has a frosted panel floating over something. I spent a few weeks rebuilding the effect properly for a project, and most of what I found online stops at one line:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight css"&gt;&lt;code&gt;&lt;span class="nt"&gt;backdrop-filter&lt;/span&gt;&lt;span class="o"&gt;:&lt;/span&gt; &lt;span class="nt"&gt;blur&lt;/span&gt;&lt;span class="o"&gt;(&lt;/span&gt;&lt;span class="err"&gt;16&lt;/span&gt;&lt;span class="nt"&gt;px&lt;/span&gt;&lt;span class="o"&gt;);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Which gives you a gray rectangle. That's not what makes Apple's version look like glass, and figuring out the difference took me longer than it should have. So here are the six techniques I ended up with, roughly in order of how well they're supported, along with the things that wasted my time.&lt;/p&gt;




&lt;h2&gt;
  
  
  1. The plain glassmorphism card
&lt;/h2&gt;

&lt;p&gt;Everyone knows this one, but there are three parts to it and most implementations ship only the first.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight css"&gt;&lt;code&gt;&lt;span class="nc"&gt;.glass-card&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nl"&gt;position&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;absolute&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="py"&gt;inset&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;20%&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;border-radius&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;16px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="py"&gt;backdrop-filter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;16px&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;saturate&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;180%&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="nl"&gt;-webkit-backdrop-filter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;16px&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;saturate&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;180%&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="nl"&gt;background-color&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0.08&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;

  &lt;span class="nl"&gt;border&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;1px&lt;/span&gt; &lt;span class="nb"&gt;solid&lt;/span&gt; &lt;span class="n"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0.12&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="nl"&gt;box-shadow&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt; &lt;span class="m"&gt;8px&lt;/span&gt; &lt;span class="m"&gt;32px&lt;/span&gt; &lt;span class="n"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0.2&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="nl"&gt;pointer-events&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;none&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;iframe height="600" src="https://codepen.io/devyatov/embed/vEgbxzW?height=600&amp;amp;default-tab=result&amp;amp;embed-version=2"&gt;
&lt;/iframe&gt;
&lt;/p&gt;

&lt;p&gt;The &lt;code&gt;saturate(180%)&lt;/code&gt; is the part I kept forgetting, and it turns out to be the whole trick. Blurring averages colors together, and averaging colors drains saturation out of them — so a pure blur comes out looking like dirty plastic rather than glass. Pushing saturation back up compensates. Drag it down to 100% in the pen above and you'll see the effect just die.&lt;/p&gt;

&lt;p&gt;The background tint matters for a similar reason. With a fully transparent background you get a blur but no surface — nothing reads as a physical pane sitting there. Something around 8% white is enough to suggest one without washing out whatever is behind it.&lt;/p&gt;

&lt;p&gt;Wrapped in React, so the numbers are adjustable:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;use client&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="kd"&gt;type&lt;/span&gt; &lt;span class="nx"&gt;GlassCardProps&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;?:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;saturate&lt;/span&gt;&lt;span class="p"&gt;?:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;opacity&lt;/span&gt;&lt;span class="p"&gt;?:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;radius&lt;/span&gt;&lt;span class="p"&gt;?:&lt;/span&gt; &lt;span class="kr"&gt;number&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;};&lt;/span&gt;

&lt;span class="k"&gt;export&lt;/span&gt; &lt;span class="k"&gt;default&lt;/span&gt; &lt;span class="kd"&gt;function&lt;/span&gt; &lt;span class="nf"&gt;GlassCard&lt;/span&gt;&lt;span class="p"&gt;({&lt;/span&gt;
  &lt;span class="nx"&gt;blur&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;16&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;saturate&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;180&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;opacity&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mf"&gt;0.08&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="nx"&gt;radius&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;16&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
&lt;span class="p"&gt;}:&lt;/span&gt; &lt;span class="nx"&gt;GlassCardProps&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="k"&gt;return &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;
      &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;styles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;card&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="na"&gt;style&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;borderRadius&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;radius&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;backdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`blur(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;px) saturate(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;saturate&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;%)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;WebkitBackdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`blur(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;px) saturate(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;saturate&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;%)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;backgroundColor&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`rgba(255, 255, 255, &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;opacity&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;Two things that bit me here. An ancestor with &lt;code&gt;overflow: hidden&lt;/code&gt; can clip the backdrop region, which produces a panel that looks like it's blurring nothing — I chased that for an hour before checking the parent. And &lt;code&gt;backdrop-filter&lt;/code&gt; creates a containing block, so anything &lt;code&gt;position: fixed&lt;/code&gt; inside it starts behaving oddly. Safari still wants the &lt;code&gt;-webkit-&lt;/code&gt; prefix, but support is otherwise fine everywhere in 2026.&lt;/p&gt;




&lt;h2&gt;
  
  
  2. Making the edges fade
&lt;/h2&gt;

&lt;p&gt;Actual frosted glass doesn't stop at a crisp border, and once you notice that, hard-edged panels start looking cheap.&lt;/p&gt;

&lt;p&gt;The fix is &lt;code&gt;mask-image&lt;/code&gt;. What makes it work is that the mask applies to the element &lt;em&gt;including&lt;/em&gt; its backdrop filter — so the blur itself fades out, rather than you covering a blurred rectangle with a gradient and hoping nobody looks closely.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;inner&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;100&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="nx"&gt;feather&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="c1"&gt;// feather: 0–80&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;maskImage&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt;
  &lt;span class="s2"&gt;`radial-gradient(ellipse at center, black &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;inner&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;%, transparent 100%)`&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;
  &lt;span class="na"&gt;style&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;borderRadius&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;radius&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;backdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`blur(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;px) saturate(180%)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;WebkitBackdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`blur(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;px) saturate(180%)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="nx"&gt;maskImage&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;WebkitMaskImage&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;maskImage&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;iframe height="600" src="https://codepen.io/devyatov/embed/XJpOMPm?height=600&amp;amp;default-tab=result&amp;amp;embed-version=2"&gt;
&lt;/iframe&gt;
&lt;/p&gt;

&lt;p&gt;One property, and the thing goes from "blurred rectangle" to something that looks like frost spreading across a surface. The catch is that the mask eats your border along with everything else, so if you want a visible edge you either keep the feather low or draw the border on a sibling element that isn't masked.&lt;/p&gt;




&lt;h2&gt;
  
  
  3. Blur that ramps up instead of starting all at once
&lt;/h2&gt;

&lt;p&gt;A single &lt;code&gt;backdrop-filter&lt;/code&gt; is uniform across the element, which is wrong for the most common case: content passing under a sticky header, or fading out at the bottom of a hero image. There you want the blur to &lt;em&gt;build&lt;/em&gt;, so text dissolves gradually rather than hitting a wall.&lt;/p&gt;

&lt;p&gt;CSS still has no gradient blur. What works is stacking several layers, each blurred slightly more than the last, each masked with a linear gradient that exposes only its own slice:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;increment&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;100&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="nx"&gt;divCount&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;direction&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nx"&gt;position&lt;/span&gt; &lt;span class="o"&gt;===&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;top&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt; &lt;span class="p"&gt;?&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;to top&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt; &lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;to bottom&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

&lt;span class="k"&gt;for &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kd"&gt;let&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="nx"&gt;divCount&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt;&lt;span class="o"&gt;++&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;blur&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mf"&gt;0.0625&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nx"&gt;strength&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;p1&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;round&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;increment&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="nx"&gt;increment&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;p2&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;round&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;increment&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;p3&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;round&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;increment&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="nx"&gt;increment&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;p4&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nb"&gt;Math&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;round&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="nx"&gt;increment&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="nx"&gt;i&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="nx"&gt;increment&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="mi"&gt;10&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="kd"&gt;let&lt;/span&gt; &lt;span class="nx"&gt;gradient&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;`transparent &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;p1&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;%, black &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;p2&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;%`&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;p3&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;100&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="nx"&gt;gradient&lt;/span&gt; &lt;span class="o"&gt;+=&lt;/span&gt; &lt;span class="s2"&gt;`, black &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;p3&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;%`&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="k"&gt;if &lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="nx"&gt;p4&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;=&lt;/span&gt; &lt;span class="mi"&gt;100&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="nx"&gt;gradient&lt;/span&gt; &lt;span class="o"&gt;+=&lt;/span&gt; &lt;span class="s2"&gt;`, transparent &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;p4&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;%`&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="kd"&gt;const&lt;/span&gt; &lt;span class="nx"&gt;mask&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="s2"&gt;`linear-gradient(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;direction&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;, &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;gradient&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;

  &lt;span class="nx"&gt;divs&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;push&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;
      &lt;span class="na"&gt;key&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;i&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="na"&gt;className&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;styles&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nx"&gt;layer&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
      &lt;span class="na"&gt;style&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
        &lt;span class="na"&gt;maskImage&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;mask&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;WebkitMaskImage&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nx"&gt;mask&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;backdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`blur(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;toFixed&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;3&lt;/span&gt;&lt;span class="p"&gt;)}&lt;/span&gt;&lt;span class="s2"&gt;rem)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
        &lt;span class="na"&gt;WebkitBackdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`blur(&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;toFixed&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="mi"&gt;3&lt;/span&gt;&lt;span class="p"&gt;)}&lt;/span&gt;&lt;span class="s2"&gt;rem)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
      &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;iframe height="600" src="https://codepen.io/devyatov/embed/emgxvLm?height=600&amp;amp;default-tab=result&amp;amp;embed-version=2"&gt;
&lt;/iframe&gt;
&lt;/p&gt;

&lt;p&gt;The overlapping is the important bit — each layer's mask extends one increment into its neighbors', so the seams cross-fade instead of banding. My first version had them meeting exactly edge to edge and you could count the steps.&lt;/p&gt;

&lt;p&gt;Seven layers turned out to be where I stopped seeing steps. Going higher just costs compositing nobody perceives, and it does cost: this is N stacked &lt;code&gt;backdrop-filter&lt;/code&gt; layers, each one a separate composited pass. On a small fixed header it's a non-issue. Full-screen at 20 layers on a mid-range Android, it very much is, and you won't find that out on your laptop.&lt;/p&gt;




&lt;h2&gt;
  
  
  4. Actual refraction, using SVG
&lt;/h2&gt;

&lt;p&gt;Blur can't refract. Refraction means displacing pixels, and blur averages them — different operations, and no amount of blur will get you the bending you see at the edge of Apple's glass.&lt;/p&gt;

&lt;p&gt;SVG filters have done displacement for over a decade, and no WebGL is involved:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;svg&lt;/span&gt; &lt;span class="na"&gt;aria-hidden&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"true"&lt;/span&gt; &lt;span class="na"&gt;style&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;position&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;absolute&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;width&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="na"&gt;height&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;defs&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;filter&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;filterId&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="na"&gt;x&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"-10%"&lt;/span&gt; &lt;span class="na"&gt;y&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"-10%"&lt;/span&gt; &lt;span class="na"&gt;width&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"120%"&lt;/span&gt; &lt;span class="na"&gt;height&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"120%"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;feTurbulence&lt;/span&gt;
        &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"fractalNoise"&lt;/span&gt;
        &lt;span class="na"&gt;baseFrequency&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="na"&gt;numOctaves&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="mi"&gt;3&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="na"&gt;result&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"noise"&lt;/span&gt;
      &lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
        &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;animate&lt;/span&gt;
          &lt;span class="na"&gt;attributeName&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"baseFrequency"&lt;/span&gt;
          &lt;span class="na"&gt;values&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;;&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mf"&gt;1.4&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mf"&gt;1.2&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;;&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt; &lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;frequency&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;`&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
          &lt;span class="na"&gt;dur&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"6s"&lt;/span&gt;
          &lt;span class="na"&gt;repeatCount&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"indefinite"&lt;/span&gt;
        &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;feTurbulence&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
      &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;feDisplacementMap&lt;/span&gt;
        &lt;span class="na"&gt;in&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"SourceGraphic"&lt;/span&gt;
        &lt;span class="na"&gt;in2&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"noise"&lt;/span&gt;
        &lt;span class="na"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
        &lt;span class="na"&gt;xChannelSelector&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"R"&lt;/span&gt;
        &lt;span class="na"&gt;yChannelSelector&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"G"&lt;/span&gt;
      &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
    &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;filter&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;defs&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;svg&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;

&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt; &lt;span class="na"&gt;style&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt; &lt;span class="na"&gt;filter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`url(#&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;filterId&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt; &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;children&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;iframe height="600" src="https://codepen.io/devyatov/embed/MYJLpqg?height=600&amp;amp;default-tab=result&amp;amp;embed-version=2"&gt;
&lt;/iframe&gt;
&lt;/p&gt;

&lt;p&gt;&lt;code&gt;feTurbulence&lt;/code&gt; generates Perlin-ish noise, and &lt;code&gt;feDisplacementMap&lt;/code&gt; reads the red and green channels of that noise to decide how far to shift each source pixel. Animating &lt;code&gt;baseFrequency&lt;/code&gt; through SMIL makes the whole surface breathe, with no JavaScript at all — which still feels like cheating to me.&lt;/p&gt;

&lt;p&gt;Two things I'd tell my past self. First, generate the filter ID per component instance; &lt;code&gt;useId()&lt;/code&gt; is fine if you strip the colons out, since they're awkward inside &lt;code&gt;url()&lt;/code&gt;. I had two of these on one page sharing an ID and spent a while wondering why the second one was ignoring its props. Second, grow the filter region — &lt;code&gt;x="-10%" width="120%"&lt;/code&gt; gives displaced pixels somewhere to land. At the default region they get clipped and you get a hard edge in the middle of an organic effect.&lt;/p&gt;

&lt;p&gt;This works everywhere, which makes it the most practical way to get real distortion on the web.&lt;/p&gt;




&lt;h2&gt;
  
  
  5. SVG filters inside backdrop-filter
&lt;/h2&gt;

&lt;p&gt;This is the one that finally looked like Apple's glass to me, and also the one I can't ship.&lt;/p&gt;

&lt;p&gt;&lt;code&gt;backdrop-filter&lt;/code&gt; accepts &lt;code&gt;url(#filter)&lt;/code&gt;, which means you can run a whole filter chain against the &lt;em&gt;backdrop&lt;/em&gt; rather than against the element's own content. Turbulence, displacement, blur:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;filter&lt;/span&gt; &lt;span class="na"&gt;id&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;filterId&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="na"&gt;x&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"-20%"&lt;/span&gt; &lt;span class="na"&gt;y&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"-20%"&lt;/span&gt; &lt;span class="na"&gt;width&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"140%"&lt;/span&gt; &lt;span class="na"&gt;height&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"140%"&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;feTurbulence&lt;/span&gt;
    &lt;span class="na"&gt;type&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"fractalNoise"&lt;/span&gt;
    &lt;span class="na"&gt;baseFrequency&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"0.012 0.012"&lt;/span&gt;
    &lt;span class="na"&gt;numOctaves&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="mi"&gt;3&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="na"&gt;seed&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="mi"&gt;2&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="na"&gt;result&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"noise"&lt;/span&gt;
  &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;feDisplacementMap&lt;/span&gt;
    &lt;span class="na"&gt;in&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"SourceGraphic"&lt;/span&gt;
    &lt;span class="na"&gt;in2&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"noise"&lt;/span&gt;
    &lt;span class="na"&gt;scale&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;scale&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
    &lt;span class="na"&gt;xChannelSelector&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"R"&lt;/span&gt;
    &lt;span class="na"&gt;yChannelSelector&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"G"&lt;/span&gt;
    &lt;span class="na"&gt;result&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"displaced"&lt;/span&gt;
  &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
  &lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;feGaussianBlur&lt;/span&gt; &lt;span class="na"&gt;in&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"displaced"&lt;/span&gt; &lt;span class="na"&gt;stdDeviation&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="nx"&gt;blur&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt; &lt;span class="na"&gt;result&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="s"&gt;"blurred"&lt;/span&gt; &lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
&lt;span class="p"&gt;&amp;lt;/&lt;/span&gt;&lt;span class="nt"&gt;filter&lt;/span&gt;&lt;span class="p"&gt;&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;





&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight tsx"&gt;&lt;code&gt;&lt;span class="p"&gt;&amp;lt;&lt;/span&gt;&lt;span class="nt"&gt;div&lt;/span&gt;
  &lt;span class="na"&gt;style&lt;/span&gt;&lt;span class="p"&gt;=&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="na"&gt;position&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="s2"&gt;absolute&lt;/span&gt;&lt;span class="dl"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;inset&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="mi"&gt;20&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="c1"&gt;// overscan&lt;/span&gt;
    &lt;span class="na"&gt;backdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`url(#&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;filterId&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
    &lt;span class="na"&gt;WebkitBackdropFilter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="s2"&gt;`url(#&lt;/span&gt;&lt;span class="p"&gt;${&lt;/span&gt;&lt;span class="nx"&gt;filterId&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="s2"&gt;)`&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;/&amp;gt;&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;iframe height="600" src="https://codepen.io/devyatov/embed/yygZMqm?height=600&amp;amp;default-tab=result&amp;amp;embed-version=2"&gt;
&lt;/iframe&gt;
&lt;/p&gt;

&lt;p&gt;Content passing behind the panel genuinely bends at the edges. The photo smears the way it does through a real lens, and the text crossing the boundary visibly warps.&lt;/p&gt;

&lt;p&gt;The problem is that only Chromium supports SVG filters in &lt;code&gt;backdrop-filter&lt;/code&gt;. Safari and Firefox render nothing at all — not a degraded version, nothing — so this only makes sense as progressive enhancement with a plain &lt;code&gt;blur() saturate()&lt;/code&gt; fallback underneath. The pen above ships exactly that fallback, which is why it still looks like glass if you're reading this in Safari; you're just not seeing the displacement. Open it in Chrome for the real thing.&lt;/p&gt;

&lt;p&gt;Worth knowing that &lt;code&gt;@supports&lt;/code&gt; can't help you here. Safari parses &lt;code&gt;backdrop-filter: url(#f)&lt;/code&gt; perfectly happily and then renders nothing, so the feature query reports success and lies to you. I lost an afternoon to that before giving up and detecting the engine.&lt;/p&gt;

&lt;p&gt;That &lt;code&gt;inset: -20px&lt;/code&gt; is load-bearing, by the way. Displacement pulls pixels inward from the edges, and without the overscan you get transparent gutters around the panel.&lt;/p&gt;




&lt;h2&gt;
  
  
  6. Apple's actual material
&lt;/h2&gt;

&lt;p&gt;iOS 26 Safari exposes the real system material to the web through a vendor-prefixed property:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight css"&gt;&lt;code&gt;&lt;span class="nc"&gt;.apple-glass&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nl"&gt;border-radius&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;20px&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
  &lt;span class="nl"&gt;border&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="m"&gt;1px&lt;/span&gt; &lt;span class="nb"&gt;solid&lt;/span&gt; &lt;span class="n"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0.15&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="py"&gt;-apple-visual-effect&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;-apple-system-glass-material&lt;/span&gt;&lt;span class="p"&gt;;&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;

&lt;span class="k"&gt;@supports&lt;/span&gt; &lt;span class="n"&gt;not&lt;/span&gt; &lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;-apple-visual-effect&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;-apple-system-glass-material&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
  &lt;span class="nc"&gt;.apple-glass&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;
    &lt;span class="py"&gt;backdrop-filter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;12px&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;saturate&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;180%&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="nl"&gt;-webkit-backdrop-filter&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;blur&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;12px&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="n"&gt;saturate&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;180%&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
    &lt;span class="nl"&gt;background&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="n"&gt;rgba&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;255&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="m"&gt;0.08&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
  &lt;span class="p"&gt;}&lt;/span&gt;
&lt;span class="p"&gt;}&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;iframe height="600" src="https://codepen.io/devyatov/embed/LExqWBW?height=600&amp;amp;default-tab=result&amp;amp;embed-version=2"&gt;
&lt;/iframe&gt;
&lt;/p&gt;

&lt;p&gt;This isn't an approximation of the OS material, it &lt;em&gt;is&lt;/em&gt; the OS material — same specular highlights, same adaptive tinting, same dark mode behavior, none of which you have to implement. And because the &lt;code&gt;@supports not (...)&lt;/code&gt; block catches everyone else, adopting it costs you nothing. Two rules, and on the platform that defined the look, your glass looks native.&lt;/p&gt;




&lt;h2&gt;
  
  
  Bonus: the version where you give up and use WebGL
&lt;/h2&gt;

&lt;p&gt;Everything above is CSS and SVG, which is the point — it ships anywhere and costs you no dependencies. But there is a ceiling, and it's this: none of those techniques compute where light actually goes. &lt;code&gt;feDisplacementMap&lt;/code&gt; shifts pixels by a noise value, which looks organic but isn't physics.&lt;/p&gt;

&lt;p&gt;If you want real refraction, you need a shader:&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight glsl"&gt;&lt;code&gt;&lt;span class="kt"&gt;vec3&lt;/span&gt; &lt;span class="n"&gt;normal&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;normalize&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="kt"&gt;vec3&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;delta&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="n"&gt;radius&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;max&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;nz&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;)));&lt;/span&gt;
&lt;span class="kt"&gt;vec3&lt;/span&gt; &lt;span class="n"&gt;refracted&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;refract&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="n"&gt;viewDir&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;normal&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mi"&gt;1&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="n"&gt;uIOR&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;span class="kt"&gt;vec2&lt;/span&gt; &lt;span class="n"&gt;lensUV&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;center&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;delta&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;refracted&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;xy&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;glassDepth&lt;/span&gt; &lt;span class="o"&gt;/&lt;/span&gt; &lt;span class="n"&gt;abs&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;refracted&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="n"&gt;z&lt;/span&gt;&lt;span class="p"&gt;);&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;That's Snell's law, one line, built into GLSL. Feed it a hemisphere normal and an index of refraction and you get a lens rather than a smear — drag the IOR slider in the pen and watch the sphere go from window glass to something closer to a marble.&lt;/p&gt;

&lt;p&gt;&lt;iframe height="600" src="https://codepen.io/devyatov/embed/EaZrWpK?height=600&amp;amp;default-tab=result&amp;amp;embed-version=2"&gt;
&lt;/iframe&gt;
&lt;/p&gt;

&lt;p&gt;No Three.js in there — one full-screen quad and about 120 lines of GLSL, because a sphere that's decided entirely in the fragment shader doesn't need a geometry library. The trade is the obvious one: a WebGL context, a canvas that isn't part of your layout, and a GPU cost that's real on low-end hardware. I cap it at 30fps and pause it off-screen, which is enough. Worth it for a hero element, absurd for a nav bar.&lt;/p&gt;




&lt;h2&gt;
  
  
  What I'd actually keep in mind
&lt;/h2&gt;

&lt;p&gt;The thing that surprised me most is how much of this is a legibility problem rather than a rendering problem. Glass is a variable background, and if your panel floats over user content or a scrolling page, you don't control what ends up behind your text. I designed over a dark evenly-lit photo, white text looked great, and then a bright sky scrolled underneath and the text vanished. The mockup was never the worst case — test against the worst case.&lt;/p&gt;

&lt;p&gt;Performance is more nuanced than "blur is slow." &lt;code&gt;backdrop-filter&lt;/code&gt; makes the compositor read back and re-filter the region behind the element on every frame that region changes. A static panel on a static page costs nothing measurable. A blurred sticky header over a scrolling page costs on every scroll frame, on every device your users own, and stacked layers multiply that. Static blur is basically free; blur over moving content needs a real measurement on real hardware.&lt;/p&gt;

&lt;p&gt;And if you use the animated distortion, honor &lt;code&gt;prefers-reduced-motion&lt;/code&gt;. Slow continuous movement across a refracting surface is exactly the pattern that makes people queasy. Freezing the animation and keeping the material loses nothing worth having.&lt;/p&gt;

&lt;p&gt;Last thing: all of these are a function of what's behind them. They look fantastic over a saturated photo and nearly invisible over flat gray, so evaluate them on your real backgrounds, not on a gradient you picked because it made the demo pop.&lt;/p&gt;




&lt;p&gt;I put live demos of all of these with sliders for every parameter — plus a Three.js &lt;code&gt;MeshTransmissionMaterial&lt;/code&gt; torus I couldn't fit in here — at &lt;strong&gt;&lt;a href="https://devpavel.com/docs/glass-effects" rel="noopener noreferrer"&gt;https://devpavel.com/docs/glass-effects&lt;/a&gt;&lt;/strong&gt;, with copy-paste code in React TS, React JS and vanilla.&lt;/p&gt;

&lt;p&gt;Curious where the performance wall actually is for other people. If you've shipped blur over scrolling content, did it cost you anything real on mobile?&lt;/p&gt;

</description>
      <category>css</category>
      <category>webdev</category>
      <category>frontend</category>
      <category>ui</category>
    </item>
  </channel>
</rss>
