We can finally animate CSS gradient

^{Find out more CSS tricks at css-tip.com}

Thanks to the new @property defined in the CSS Properties and Values API Level 1 specification we can now have transition with custom properties (aka CSS variables).

@property --my-var {
  syntax: '<integer>';
  inherits: false;
  initial-value: 0;
}

All the trick is within the syntax part that allows us to explicitly define the type of the property thus the browser will know how to do the interpolation between values (the transition we want to have)

Specifies the syntax of the custom property registration represented by the @property rule, controlling how the property’s value is parsed at computed value time.

Considering this we simply need to use the variables inside the gradient definition and animate them.

Animate the colors

We use <color> for the syntax

Animate the color size

We can use <percentage>, <length> or <angle> based on each use case

Animate the direction

We use <angle>

Animate the position

We use <percentage> or <length>

---

As you can see, it's easy and the code looks like the following in all the cases:

/* we define the variable */
@property --a{
  syntax: '<percentage>'; /* its type */
  inherits: false;
  initial-value: 10%; /* the initial value */
}
/**/
.box {
  transition:--a 0.5s; /* we add transition to it */
  background:linear-gradient(red var(--a),blue); /* we use it inside the gradient */
}
.box:hover {
  --a:50%; /* we update on hover */
}

We can have complex animation:

and use keyframes

Let's wait for this to be supported on Firefox and we can do a lot of magic with 😉

Comments

[GrahamTheDev]

Finally I can launch my "acid trip rave party" website without relying on JavaScript to provide the psychedelic background!

Seriously though I can't wait to be able to use this (the @property methods, not the spinning gradients 😋) but it might be a while before support is good enough 😪

[Temani Afif]

I would say you will be able to use it within this year. The firefox team won't take too long to bring support to this ;)

Concerning the spinning gradients, it's a technique to hypnotise users to oblige them to give me some likes (it's working ;) )

[Robert McGovern]

The firefox team won't take too long to bring support to this ;)

Nearly 3 years later and we are still waiting on Firefox sigh

At least we are up to 87% coverage

[GrahamTheDev]

What is the roadmap for chrome and safari on iOS, I couldn’t find it as it doesn’t seem to work there yet 😔

[Temani Afif]

Ah forget the iOS people. You can find more details here: ishoudinireadyyet.com/ (it's the Properties & Values API)

[Bilelz]

thanks! really amazing

[Andreas]

A little typo in your code example above the complex animation section: you define --c but then use --a.

Great article though, thanks!

[Temani Afif]

Thanks, updated

[Bruno]

Hello, I encountered a weird issue using this type of animation in a nextjs build. In development it works, but in production it doesn't work, as in it goes in huge chunks or it doesnt run at all. Has anyone encountered this kind of issue?

[Bijan]

Super excited to see how this gets implemented!

[𝐍𝐚𝐭𝐚𝐥𝐢𝐞 𝐝𝐞 𝐖𝐞𝐞𝐫𝐝]

Oh this is exciting!

[CarolMcKay]

Whoa! Wonderful! I have seen @property but thankyou for explaining it so well.

[eboye]

Cool, but I'll wait Firefox support to start tickling around :D

[Rahul]

This is an amazing article. You should have submitted to CSS-Tricks.com

[Mika]

This looks good! Thanks for sharing

[Temani Afif]

welcome :) say tuned, more fancy tricks are coming ;)