I understand if you want full resolution for art, but my internet connection begs you to become familiar with an image compressor like TinyPNG or similar
it's cheap and easy, if you've got big files embedded in a page (like high-resolution images/video/audio), you can just tell the browser to only load them when needed
CSS has a property called image-rendering and one of the values is pixelated.
The image is scaled with the "nearest neighbor" or similar algorithm to the nearest integer multiple of the original image size, then uses smooth interpolation to bring the image to the final desired size. This is intended to preserve a "pixelated" look without introducing scaling artifacts when the upscaled resolution isn't an integer multiple of the original.
So if you want to have your pixelart pieces on your website keep their look when you make them bigger/smaller1, image-rendering: pixelated is your best friend 
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assuming you use integer increments of size. I'm assuming most pixelart artists are aware that resizing to 1.2x or 3.6x the size is Not A Good Time but you never know haha
