Fireworks is not an option (any more). I share DeeKay’s opinion from 2 comments above.

Ask Google how they like slow loading websites these days.

Unbelievable, that question was asked in 2010 and in 2013 we still need 3rd party converters like ImageAlpha to make small transparent PNGs for the web. That complicates our web development workflow.

I was fearing that the new Adobe Cloud System could slow down the CS development, including DW, AI and PS, since there are not paid upgrades any more that bring fresh money but now the money comes automatically, month by month.
I hope you prove me wrong. :-)

Come on, Adobe! PNG8 with Alpha is NOT Rocket science! I can do it by hand, although it’s work intensive (and Fireworks fails, like mentioned!). You simply dither Alpha in X levels and the Picture in Y colors, while X*Y may never exceed 256. It just needs one extra pulldown for Transparency levels (max. colors and transparency levels adjust whenever one of the other values is adjusted!), three new options for Alphachannel-Dither in the Transparency pulldown (error diffusion, pattern, noise) and maybe an extra slider for the strength of the alphachannel-dither, so you can adjust that separately from the picture dithering. Ofcourse, the color picker would need an extra transparency slider, too, to be able to manually adjust that per color in the palette area!…

Two reasons why semi transparency is essential to me.

1) File size is way lower than 32bit. – Sometimes the image has too much banding to be a png8 but I need to decide that on a per use basis.

2) Although ie6 ignores the semi transparency completely, it at least looks better than they grey box around png32. On things like icons this is what I’d prefer.

Please, please please add this support to the save for web.

Thanks

I think the other comments on this post more than suffice to extoll the advantages of bringing full-transparency to the PNG-8 format in PhotoShop/ImageReady in terms of the intrinsic virtues of the format itself – I’d even go as far as saying it’s Adobe’s responsibility to web standards to promote the use of this format as a means of lightening the bandwidth load for millions of websites across the world.

The simplest example I can think of as a use-case that would benefit, in particular on mobile sites, is that of a round button image on a background containing a horizontal stripe. The transparency tool currently available in ImageReady would simply not accommodate saving the button in PNG-8 format with adequate alpha transparency to account for the stripe – so a PNG-24 image has to be created instead or, worse, the stripe has to be built into the button. How 1997!

Taking therefore both the advantages of the format and the applications as self-evident, I’d like to add a note about workflow to address the question of “how I’d use it/why it’s important for it to be a part of PhotoShop:” as more and more designers board the “web development” teams at mainstream companies, they are taking on more of the web image optimization responsibilities that “webmasters”/developers and hackers used to claim as their speciality/dark art.

With this simple fact in mind concerning the evolution of workflows, simplifying the process of image development is of renewed importance: it is not in the typical purview of designers to fiddle with tools that interfere with the creative process itself, and given that PS/AI are the de facto standards for asset creation, it seems critical that their export tool, ImageReady, be up to snuff when it comes to producing the best, most optimized renditions of their art. The designers I’ve worked with would easily adopt a checklist of settings to use in exporting images from their creation tool; it’s a much harder sell for me to teach them an entirely new tool such as Fireworks only to meet a goal specific to my agenda as “webmaster” overseeing site performance. It’s not that they couldn’t learn it, it’s that it complicates the process.

CS9 maybe?

While waiting i use this little open source app called ImageAlpha (Mac) (Google it) that converts 24-bits PNGs with alpha to 8-bits PNG with alpha with amazing results. Saving almost 70-80% on every file i drop on it.