So in our blog post Shrink your Images on a Mac, we did briefly explain what bandwidth is and why it’s important to conserve it by pulling the size of your images down. But here is a bit of an overview for those who very little about what it is and it’s importance.


Bandwidth, what is it?

When signing up for a website you are giving a certain amount of bandwidth. And bandwidth is used when people come to your website, so just like on your computer you have a certain amount of memory you can use for files, movies, documents and every time you open up a file it takes a little bit of time to open that file.

Similarly, you have an allocated amount of memory on your website, (this is the bandwidth) and some of that memory (depending on the type of website you have) is used when you upload all your files mainly images, and the other memory is used when people view your products. It is also used when people send you massive images and attachments through email because your emails are all backed up on a server for around 15-30 days


The link between large Images & Bandwidth

So if you have a massive image, everyone that see’s that image is actually downloading that image into their browser. (Talking about Cache: A web cache is a mechanism for the temporary storage (caching) of web documents, such as HTML pages and images, to reduce bandwidth usage, server load, and perceived lag.) So this image is then downloaded from your bandwidth then goes into the cache of the viewers’ computer. So every other time they have a look at that same product the computer doesn’t have to re download that image. (You might notice that when you clear you’re cache, going to websites that you visit a lot, may take that little bit longer, because you’re computer had to re cache and process all those image son the websites.)


Not an Optimised image

So if you had no more than 10 people coming to your website a day it wouldn’t be much of an issue to have slightly large files, but if you’re website is doing well (pat on the back for you!) you might have traffic up to the hundreds, and then a lot of bandwidth is being used. Why? Because dozens of large images are being downloaded and viewed by hundreds of people. Lets say your image is 1.5 MB (seems small) and lets say you have 15 images on the main pages of your website that’s 22.5 MB worth of images, now lets say you get 150 people come to your website, that’s 3.3 GB used in a day, and what if that happens every day for a month? That’s around 94 GB for the month. And your average monthly bandwidth allowance is around the 10 GB month, by those stats you’ve already crashed your website.


A nice optimised Image

Now Lets compare that to an optimised image (remember optimsing an image doesn’t lose out in quality, so we’re talking same same quality image, just optimised for web) So now lets say your lovely new optimised image is 126.7 KB and now lets say you have 15 images on the main pages of your website that’s 1900.5 KB (Or 1.8 MB that’s the size of one of your normal pictures NOT optimaised) worth of images, now lets say you get 150 people come to your website, that’s 0.2 GB used in a day, and what if that happens every day for a month? That’s around 7.6 GB for the month.

So do you see the difference there? You are saving a little over 86 GB (that’s equivalent to 28 full feature films!) The cost savings you’d be making are huge! Well into the hundreds!


The Math

shutterstock_114912478Massive images + loads of traffic = Lots of bandwidth being used plus a slow loading site that people may not have the patience to look around and potentially customers lost.

But optimised images + loads of traffic = Smooth running website, easy load, (You don’t loose out on quality of images) and savings on your side.

So going by the stats mentioned above that’s a 92% saving in bandwidth, and at least $500 back into your pocket because you read this post and now know you should be optimising your images!