Animated .GIF vs Spritesheet + JS/CSS

Question

Which will scale best for performance, file-size, (and my sanity): Animated .gifs or a spritesheet with animations using CSS (and JS when need be)?

Filesize

So, I'm honestly not sure which will be better here since I don't understand the compression of frames in .gif. My guess would be that they would end up about equal if I can swing it right, but if this is wrong, or if this is a factor for a different reason let me know.

The main advantage here, in my mind, goes to Spritesheets as I would be able to include multiple animations on a single sheet (and we're talking hundreds of animated sprites here). And based on one of my previous questions, I know that I can easily pull out a single frame in CSS using image-rect(). Where as with a .gif file I really can only include one animation since each will likely have a different duration.

Addendum: Also, some of the animations repeat for a given sprite, so the spritesheet would only have to have one copy of the frames, where as a .gif would need to have all the frames (at least to my knowledge).

Performance

Guessing here again, my intuition tells me that animated .gifs are going to be significantly faster as I won't have to manage all the animations at the same time I'm doing a lot of JS code for other things. But, I don't know for sure, maybe browsers take a significant hit with 30+ animated .gifs.

My Sanity

The spritesheets are made for me, so my work would be high in the beginning (writing and animation engine and hand coding one/each sheet). But once written, it is usable for good and a change in a spritesheet requires minimal changes to code.

On the other hand, animated .gif files are not a cake to make in Photoshop (if you have a better program, please let me know). And each one must be hand made and is a long process. But, once they are made, I don't really have to change them. My spritesheets aren't likely to change very quickly, so chances are it will be a one and done.

My Question (tl;dr)

Which is going to scale better to the hundreds of animations in terms of filesize (including HTTP header transfer as it will go over the web), performance in modern browsers, and ease of creation (lowest priority, but if you can make my job easier, or argue to this, I would be grateful), Animated .gif files built from spritesheets, or simply using CSS and the spritesheets I already have?

Examples

VS

Answer 1

As I was curious, I implemented it in javascript.

JsFiddle demo (edited image host as per comments).

What I found out:

• It works! And better than expected.
• The CPU usage is actually low (did not test it in IE6 dinosaur and I'm sure it would require "fixes").
• The size can be cut off, and/or quality can be increased, significantly (source-dependent).
• Unlike Mikey G.'s concept, this works even if you zoom in/out (try it in both).
• It allows variable frame duration just like a gif.
• With more work, it could even have a player-like API (pause/resume, fastforward, skip, etc...).
• Leverages other formats: 8-bit alpha PNG, progressive JPEG, <canvas>, SVG, WebP...

More info in the JsFiddle demo page.

Answer 2

Gif animations can repeat sprites, they can also use partial frame updates, and positioning the same sprite at different positions. If you simply want to display a non-interactive animation I'd say animated gifs have all the advantages, except for colour, you are forced to use a 256 colour palette.

I remember using Microsoft GIF Animator, that is certainly easy to use. I don't know anything about Photoscape, but word on the net is that that is a good slightly more heavy alternative.

Answer 3

Animated gifs only give you binary transparency (a pixel is transparent or totally opaque). That's why most animated gifs look bad on transparent backgrounds because you cannot apply antialiasing (like your squirrel, some antialiasing there would do wonders).

If you want to have PNG-24 transparency quality you have to go with animated sprites.

Also, animaged sprites performs really well if you draw them on a canvas. Look this: http://seb.ly/demos/bunnybench/bunnies_canvas.html

Answer 4

Just wanted to weigh in on this. There are many scenarios in which you have multiple animations on one page. In the scenario of having multiple animations on the same page that are interactive. It is better to use a sprite sheet with CSS animations than gifs. Here are my demos:

http://clubsexytime.com/projects/eyetracker_gif/

http://clubsexytime.com/projects/eyetracker_sprite/

as you can see the sprite version handles the roll overs with ease while the GIF based version kurchunks to a halt.

Again, this is just one scenario, but thought it might be useful. Also it acts as a good code snippet.

Thank.

Answer 5

One other issue related to CSS sprites, at least in the current browsers, is scaling "jitter". You can scale the GIF file to whatever size you need (presumably smaller), but if you try to scale the CSS sprite you run into jitter because of rounding errors (background-position is based on the the scaled coordinates, not the original). If someone knows another way of handling scaled animated sprites, that would be great to know.

ImageMagick does a great job of creating animated GIFs or sprites.

Answer 6

I'd take a look at this:

http://adamducker.com/blog/7/animated-gif-for-css-sprites/

I personally think you'd be crazy to use a spritesheet, but i guess it depends on how many animated gifs you'd have to bring over otherwise

I don't know what your limitations are, but here's a fiddle using CSS3 step() to animate a spritesheet:

http://jsfiddle.net/simurai/CGmCe/