This question is related to this one, but is a bit different.
In the layout (archive page) for a WordPress project I’m working on right now there’s a couple of image sizes that do not appear anywhere else. They are quite (by tens of pixels) close to the sizes that we already have registered — let’s say, we have 210×300 already and the new size is 230×300. There’s also another new image size which doubles that in height and could be also replaced by an already existing image size.
I know that having a lot of differently sized elements might not be good in terms of design consistency — so that could be one argument against it.
But, looking more from a practical side, are there any performance related concerns in adding more and more image sizes via add_image_size? Currently we have 8 custom image sizes, and I’m not sure whether it’s optimal to add more of them.
Thanks!
1 Answer
Depends. One argument could be that if the requested page use all sizes then there will be a lot of image calls (slower response, bandwidth etc) but you can bypass that i.e. by loading images with JS. Also more sizes means more disk space usage. I don’t think there is any significant performance concern related to back-end, meaning the db calls / queries etc.
Also if the images are compressed from the begging a few pixels down in width or height won’t be a difference in performance.
You can have an image with 600×900 dimension and cover a lot of intermediate sizes adjusting with CSS and keep a good aspect ratio and have a good quality for retina monitors. Better to have a bigger, in dimension, image and shrink it than to have a smaller image and scale it up.
