We’ve all done it! Uploaded an image to a web page and then realised later that the file size is massive.
How long does it take for your web page to load when you have a few whopping great big images on there?
I remember a client from the early days who had a 1 page website, every week he posted a flyer he had scanned promoting a venue in London and it’s weekly activities. Each flyer he uploaded was over 5mb so after the 1st year his home page was over 250Mb. Every person who viewed his one page website had to download the full 250Mb. He started to complain that his page was taking ages to load and I pointed out the reason why.
Obviously this guy was not aware that he should have reduced the file size of the scanned images prior to uploading them.
Note: As an aside, regardless of the image format used to transfer the data from the server to the client, when the image is decoded by the browser, each pixel always occupies 4 bytes of memory. This can be an important constraint for large images and devices which do not have a lot of available memory – for example, low-end mobile devices.
There are many online image optimisers available on the net.
Smush.it: Image optimizer WordPress plugin. To name a few.
There is also an image optimiser you can download too, called RIOT Radical Image Optimization Tool
This tool also has an option to bulk optimise images. It’s only available for Windows at the moment.