Can you add noise to a CSS3 gradient?

Solution:

This is by far the most hassle free and best way to implement this. It is purely CSS and very very simple to do, no extra files - nothing. Ok, it's not the best way possible, but it works very well, very reliable (never failed when testing across very old browsers) and very fast to load.

Found it a few months ago, and used it ever since, simply copy and paste this code in to your CSS.

background-image: url(data:image/png;base64,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);

Then add your background color

background-color:#0094d0;

Demo: JSFiddle

Source: https://coderwall.com/p/m-uwvg


There's no current way in css to add 'noise' to a background.

An alternative solution would be to create a transparent noise png in your graphic editor. Then apply that graphic as a background to a <div>. You would then need to place that <div> over the entire area of the <body> which should then give an appearance of a gradient with noise.


Creating Textures (Noise) Using SVG Filters & CSS Gradients

You want noise in your gradient? You're in luck!

Perlin noise is a type of gradient noise. The SVG standard specifies a filter primitive called <feTurbulence>, which implements the Perlin function. It allows the synthesis of artificial textures like clouds or marble—the noise you want.

Step 1: Define an SVG Graphic

Create a small SVG file called noise.svg.

<svg
  xmlns='http://www.w3.org/2000/svg'
  xmlns:xlink='http://www.w3.org/1999/xlink'
  width='300' height='300'>

    <filter id='n' x='0' y='0'>
            <feTurbulence
              type='fractalNoise'
              baseFrequency='0.75'
              stitchTiles='stitch'/>
    </filter>

    <rect width='300' height='300' fill='#fff'/>
    <rect width='300' height='300' filter="url(#n)" opacity='0.80'/>
</svg>

This graphic defines two rectangles. The first is filled with a solid color. The second is translucent with the noise filter applied. The second rectangle is overlayed on the first to provide a noise effect.

SVG Options

  1. Fist and most obvious is that you can change the dimensions of the graphic. However, the CSS background-repeat property can be used to fill an element, thus 300×300 should suffice.

  2. The filter's type attribute can be fractalNoise or turbulence, which specifies the filter function. Both provide a different visual, but in my opinion, the noise filter is a little more subtle.

  3. The filter's baseFrequency attribute can range from 0.5–0.9 to provide a course to fine texture, respectively. This range is visually optimal for either filter in my opinion.

  4. The first rectangle's fill can be changed to provide a different base color. Later, however, we essentially combine this color with a translucent CSS gradient, which also defines a color(s). So white is a good starting point here.

  5. The second rectangle's opacity can range from 0.2–0.9 to set the filter intensity, where a higher number increases the intensity.

At this point, you could tweak the aforementioned options, set this noise graphic as a background image via CSS, and call it a day. But if you want a gradient, like the OP, go to Step 2.

Step 2: Apply a CSS Gradient

Using the background-image property, you can set the SVG noise graphic as the background on any element and overlay a gradient. In this example, I'll apply the noise graphic to the entire body and overlay a linear gradient.

body {
    /* white to black linear noise gradient spanning from top to bottom */
    background:
      linear-gradient(rgba(255,255,255,.5), rgba(0,0,0,.5)),
      url('noise.svg');
}

The linear-gradient() function creates a pseudo image, which is stacked on top of noise.svg. The result is a translucent gradient with our noise showing through it.

CSS Options

  1. First, and most obvious, is that the defined gradient colors can be changed. However, if you want a solid color without a gradient, make the two end-point colors equal. The benefit is that you can use the same noise graphic with or without a gradient throughout a site or among projects.

  2. Multiple images, created with the *-gradient() functions, can be overlayed on the noise graphic and more than two color parameters and angles can be specified in a single gradient function to provide all kinds of cool visuals.

  3. The opacity of the gradient parameters—i.e. rgba() and hsla()—can be increased to intensify the defined color and reduce the noise level. Again, 0.2–0.9 is an ideal range.

Conclusion

This is a highly customizable and very light-weight (~400 bytes) solution that allows you to simply define noise of any color or gradient. Although there are several knobs to turn here, this is only the beginning. There are other SVG filter primitives, such as <feGaussianBlur> and <feColorMatrix>, which can provide additional results.