After a lot of tinkering, fiddling, poking, and prodding we’ve revamped the image support in gravatar. Now if you upload a GIF or a PNG we will preserve any transparency that might be in the image and serve that image to you as a PNG.
Unfortunately this does not retroactively fix existing images with black instead of transparent backgrounds. You’ll want to re-upload your transparent images, assign the new image to your email addresses. After that, give it about 30 minutes and clear your cache. Everything should work and look just fine.
Until next time – happy blogging!