A Data Save Mode for the WebBlog •
Let me answer the easy part of the question first. Let’s say we make it a toggle, like for the dark mode or something like that. That means the application has to act according to the state of this toggle. Pretty simple. When toggled on, don’t do x or show y.
Some of the biggest things you might want to hide are images. They should be compressed and lazy loading anyway. But how about not loading at all? With a data-saving mode, you could replace selected images with a button. Such a button would then fetch the corresponding image. With SVGs, one could hide or replace them with a simple word or text.
The same goes for animations. Some animations look good. Some of them take up a lot of time. They shouldn't only act according to the user's preference for reduced motion. But also have a way of disabling them on your website.
More things are considerable. And those things also depend on the opinions of the developers and users. But giving the user the ability to improve their experience by themself is good. All these things could hide behind one toggle or even a list of settings.
I understand that not every website can use that, and not every website can profit from it. But you might find something that your application doesn’t depend on. Disabling or hiding it might please some users, while others prefer the opposite. Why not give them the option to choose?