Hi, thanks for your comment.

Unfortunately, because of the limited color palette, transparency in GIF (animated or not) will look really ugly with jagged edges around the object(s). At least, this is from my experience working/editing in Photoshop, where none of the options could help to avoid it. You have to define a constant background in order to avoid the 8-bit (or less) transition between the edges and the [transparent/overlay] background. So, I strongly recommend not using it, unless really necessary.

The only “solution” to smooth it out is to use 2x, 4x or 8x over-sized image file(s) which cancels our initial effort to reduce the size in the first place and then scale it back in browser (or wherever you need it for to be displayed), assuming availability of some better scaling algorithms than simple nearest neighbor.

Depending on what you try to animate:

[1] something “real” like a live-action video scene to embed in a web page, GIF seems like easiest option, or you can use HTML5 video and some mp4 clip;

[2] or just a simple object which you can animate with some programming, forgetting GIF all the way. For example, you can animate simple objects and things with JavaScript/jQuery (like 2D/3D rotation, translation, scaling, color/hue shift…). Alternatively, some forms of animation can be achieved directly in web browser using pure HTML5 and CSS3.

So, in the web domain you already have all the tools to create animations that can fairly replace and will outperform complex GIFs with transparency and size like this in pure code (assuming no live action video), or using static “pre-rendered” PNG files, that allow you 24-bit palettes and better quality (the size might not be so small, as 8-bit PNG also sucks with alpha channel).

If you need it for something else, like animated logo to be used in a video editor, live stream or whatever, then you may consider APNG if it is supported by the editor, or some movie clip with background carefully edited/removed (assuming video container and codec support transparency support).

The alternatives exists in some areas, depending on the field of application.

I was looking for something free to improve compression, particularly in regards to handling transparency. I was using GIMP, which has some really awful handling of optimization– I was seeing some 3% improvement, whereas really crude (but still tedious) hand optimization was getting me down to like 2/3rds the original file size.

The online tools you mention are pretty bad. Particularly, they don’t let you run multiple optimizations at once. They also don’t do a better jobs of optimizing for progressive gifs (built on successive layers) than GIMP does. Nor is it worth the headache for these tiny improvements in file size.

As you mentioned, VirtualDub is the one tool that does a good job at optimizing for building layered gifs. Unfortunately, it also does some really awful things to the colors that other tools don’t do, limiting the palette really badly, and there aren’t any options for gifs, you just get what it gives you. Also difficult to use it to re-time gifs, which is pretty important when doing avi->gif (30fps is usually overkill, one shouldn’t aim for more than 10fps with a gif, I think).

Still looking for any decent tools. I think I’m stuck with hand optimization for now.