You should always compress images for ebooks and your website, but it doesn’t mean reduced in dimensions.
When you use an image compressor, your reduced image will keep its physical dimensions.
A compressor strips an image of its embedded data. Then it lowers the resolution and quality to reduce the file size.
As with all things Internet, including ebooks, smaller file sizes make for faster websites and transfer speeds.
Images for ebooks
If you publish on Amazon Kindle and use images in your ebooks, large image files will increase your overall ebook file size.
You are charged for ebook delivery by Amazon, so be aware that large ebook file sizes will quickly eat away at your ebook royalty.
This is why you need to compress images for ebooks.
The key issue with images for ebooks is to find the right balance between image quality and file size to suit where the image will appear.
For a website, an image does not need to be of high quality and resolution, but it still needs to be sharp and clear.
For an ebook, consider that it is unlikely that your ebook will be read on a high-definition device.
A Kindle ebook reader is certainly not, and many models are only black and white. So again, high resolution is definitely not necessary.
Steps before you compress an image
Before compressing an image, the most important step is to change the physical dimensions of the image. Resize it to suit where you are going to use it.
But first, make a copy of your image so you can keep the original.
You can use Preview on an Apple or Paint on a PC. Crop or resize the copied image to the dimensions you want to use. Make sure you save your resized image and perhaps give it a new file name.
There are many ways to compress a jpeg image or png images online. A quick Google search will find a lot of free sites, and most of them work very well.
I selected Online Image Optimizer to use for my example below. But many other free online apps will do a similar job for you.
Start compressing your image
My original image was nearly 1.4 megabytes, which was way too big for online use.
Let’s look now at how to use lossy compression to compress the image size. This will make it suitable to use on a website or in an ebook.
The great feature of this compression tool is that it gives you a long list of choices. Each stage shows you more file size reduction.
In the first capture, you can see that my uploaded image was 1.39 MB.
As you scroll down the image below, look at the file size on the left of each image. It is reducing a little with each slide. The app reduces my original image size incrementally.
It depends on how you intend to use an image.
But the last three optimized images still retain enough visual quality for most online applications. But with a saving of over 80% on the original file size.
However, in the last image, it is noticeable that the quality is starting to deteriorate.
I would select the third from the last image because it is the best balance between size reduction and image quality.
Then it is just a matter of right-clicking on the selected image to download it.
Now I have my image at a fraction of its original file size. But importantly, without any noticeable visible loss of quality or aspect ratio dimension.
Can you compress offline?
If you have an Apple computer, the quickest and easiest way to compress images for ebooks is to use a free application, ImageOptim.
It is a very simple drag and drop application. You can adjust the settings to suit any level of compression for jpeg, png, or gif.
Image compression to reduce image size is quick and easy with this free little app. It saves you a lot of bandwidth, which reduces the loading speed of your websites and blogs.
For ebooks, compressing all your images will reduce the Whispernet delivery charge by Amazon Kindle. So your royalty will be higher.
These are both very good reasons to learn how to compress images. It’s easy to do, so make a habit of compressing all of your online and ebook images.
What do I use?
For every image that I add to my websites or ebooks, I use ImageOptim because it is so quick and easy.
You can see my settings for it in the image above. All I need to do is drag the image file into the app, and it’s all done in less than a second.
But I have one more tool to compress images even more, which I use for all my blogs and websites.
WP Smush is a free WordPress plugin that compresses images automatically on upload to the WordPress media library.
It doesn’t do as good a job as ImageOptim by itself. But it does help by reducing my already compressed images just a little bit more.
Again, without any quality loss, which ensures that my website pages will load lightning fast.
Do you want a compressed version of your book cover to use on your website?
All you need to do is go to your book’s Amazon page and right-click on your book cover image and download it.
You will get a fully compressed version because Amazon has done all the compression work for you.
For any image you want to use online, always think first about how big it is. A large image file size will always slow things down.
It will only take you a few seconds or minutes to compress your images before you upload them to your blog or website.
Then you can be absolutely sure that your page will load faster or that you won’t lose money on your ebook sales royalty.