use multiple css filters at the same time?

I am using this.

/* Multiple filters */
backdrop-filter: url(filters.svg#filter) blur(4px) saturate(150%);

I'm trying to create utility classes in vanilla CSS and this would be helpful but it looks like it can not be done this way.

<img class="brightness-20 image-grayscale-100">
.brightness-20 {
    filter:brightness(20%);
}
.image-grayscale-100 {
    filter: grayscale(100%);
}

I'm not sure why they didn't just create a more specific property like:

filter-brightness: 20%; filter-grayscale: 100%

After some more work I came up with this solution:

/*Initalize Variables No Adjustments*/
:root {
    --blur:0px;
    --contrast:100%;
    --brightness:100%;
    --contrast:100%;
    --dropshadow:0px 0px 0px black;
    --grayscale:0%;
    --hue-rotate:0deg;
    --invert:0%;
    --opacity:100%;
    --saturate:100%;
    --sepia:0%;
}
/*Apply Defult Variables To Image*/
.filter {
    filter: blur(var(--blur)) contrast(var(--contrast)) brightness(var(--brightness)) contrast(var(--contrast)) drop-shadow(var(--dropshadow)) grayscale(var(--grayscale)) hue-rotate(var(--hue-rotate)) invert(var(--invert)) opacity(var(--opacity)) saturate(var(--saturate)) sepia(var(--sepia)); 
}
/*Override Defults*/
.brightness-20 {
    --brightness:20%;
}
.image-grayscale-100 {
    --grayscale: 100%;
}

Because it's one property named filter, every time you want to add a style to it you override it.

CSS version 1

Fortunately you can add multiple styles in some properties like background-image and filter! To get this working you'll have to put all the filter styles in one space separated filter property.

.grayscale.blur {
    filter: blur(5px) grayscale(1);
}

CSS version 2

An alternative, flexible, solution would be to create a "div soup" on purpose and set different filters in the html stack. e.g.

<div class='demo__blurwrap' style='filter: blur(5px);'>
    <div class="demo__graywrap" style='filter: grayscale(1);'>
        <img src="awesome_image.jpeg" alt="">
    </div>
</div>

CSS version 3

edit: just realised I just wrote this version with transforms, but the same idea applies.

Yet another solution is CSS vars. I wouldn't say it's ideal but it's a nice experiment. The major downside is that you need to declare a lot of variables, have default long rules for transform and nested transforms will definitely break.

// Added just for fun
setInterval(() => {
  yes_this_works_and_one_of_many_reasons_ids_are_bad.classList.toggle('translate');
}, 1000);
setInterval(() => {
  yes_this_works_and_one_of_many_reasons_ids_are_bad.classList.toggle('scale');
}, 1500);

:root {
  --scale: 1;
  --translate: 0px;
}
.box {
  background: blue;
  width: 20px;
  height: 20px;
  transform: 
    scale(var(--scale))
    translate(var(--translate), var(--translate));
  transition: transform .3s;
}
.box.translate {
  --translate: 20px;
}
.box.scale {
  --scale: 3;
}

<div 
  id='yes_this_works_and_one_of_many_reasons_ids_are_bad' 
  class='box scale translate'
></div>

Javascript

Lastly, if you were to use JavaScript to render the styles you can read the current applied filters using getComputedStyle and add more to the mix.

• Modern browser demo setting styles nicely
• Modern browser demo setting styles without respect and fix it with observers

And a relevant article - this is more for animations and not yet supported by many browsers: Additive animations

And another relevant article on css-tricks: Houdini