Image Optimization for my site

Question

I use a hosted CMS and do not have server side access so I cannot set expiry for images but was told it helps to optimize my images and improve my site speed. My question is what exactly does it mean to use image optimization? And how?

Note: I use photoshop for majority of my image editing.

Answer 1

If you don't have access to the server you won't be able to control caching. That is probably the most important aspect of optimizing the loading time of images and just leaves you with making sure your images are as small as they can be while still looking good.

The key to this is choosing the right format for your images and then using the proper compression for them. Each format has its strengths and weaknesses. Generally speaking JPEGs are good for photographs and PNGs are preferred over GIFs as they offer better compression especially if you use tools like PNGCrush.

Answer 2

I believe it means that you should take a special attention to the weight and format of your image. You should compress image as much as possible but also taking car of not loosing too much quality. For picture, jpg is the recommended format. For other image you should use png.

You should take a look on this website that automatically optimize your image from a link: http://sitereportcard.com/imagereducer.php

Answer 3

I use a CMS and do not have server side access so I cannot set expiry for images

Not necessarily true. Some apps provide ways to edit htaccess without file access, eg. WP Htaccess Editor for WordPress. You should look around at your options, if using some other system.