I noticed (with the help of Google's PageSpeed Insights) that the altmetric badges, are delivered as uncompressed PNG images inflicting a performance toll on page load times.
It would be great if the images could be compressed, in a lossless way.
From some experimentation (see attached files) the images' size could be reduced up to 70%, meaning gains at the magnitude of hundreds of KBs, especially in pages including more than one badges.
This could alleviate some concerns for integrating altmetric badges in more websites without greatly impacting performance and page load speed.
Thank you so much for writing to suggest this improvement. I have added this ticket to "Planned" as we are considering making some Badge performance improvements (as well as some other aesthetic improvements). Although we don't have a timeline for this particular task, I will be sure to let you know if we implement the changes.
Jean Liu (Product Development Manager, Altmetric)