Image files will usually have the most impact on the speed of your websites (aside from Ad/tracker scripts). Learn to slim down your images using the ubiquitous ImageMagick to make your websites faster on slow internet connections.
For the examples, I decided to use this public domain image.
There are many ways to decrease image size using ImageMagick, the
simplest is to use the
-quality option, which will compress the image
without changing the resolution. This option takes the value you want to
compress by (between 1 and 100, the lower the value, the lower the file
size). For example:
convert in.jpg -quality 50 out.jpg
Compressing the example image above results in the following file size changes:
Quality Size ---------- ------ Original 2.1M 90 1.7M 80 844K 70 588K 60 448K 50 368K 40 308K 30 248K 20 184K 10 116K
Due to the images high resolution, it is usable in this website even when highly compressed (30% quality, still looks decent in my opinion).