I wrote a PHP snippet to fetch high-resolution images from the website of the Himawari 8 satellite and combine them into one high-resolution image. The way to fetch satellite images is available here . However... The combined 4d resolution PNG image (2200x2200) is over 7 MB in size, and due to the bad connectivity between China and the US, it takes over a minute to load the image (from my server). Way too slow! Google provided a solution: the WebP image format. WebP is famous for its high compression ratio on lossless compression scenarios. After converting the 7 MB earth photo PNG file to WebP, the resulting file size is less than 700 KB. For a photo with resolution 2200x2200, this is pretty small. But... Some browsers, including IE and Firefox, don't support WebP,...