How important are compressed images for website speed?
Nowadays visitors expect your website to be fast, otherwise, they will leave in no time. Besides, a faster website leads to more conversions and a better user experience. An easy way to make your website faster is to compress images. But what are compressed images, how does it work and why do you need it?
What is image compression?
Each image requires a certain amount of memory to be stored. The amount of required allocated memory is based on the image’s dimensions, how many pixels the image contains, and the number of colors available per pixel (known as bit depth). Image compression is the process of reducing the amount of memory that an image takes up. With compressed images, the storage impact on your hard drive can be reduced, sending and uploading images in emails will be faster, and your website performance is improved.
Lossy versus lossless compression
There are two ways of image compression, lossy and lossless compression. With lossy compression, some image data will be lost in the compression process. The bytes of a graphic will be minimized because the number of colors will be reduced and converted to a much smaller indexed-color image. The benefit of lossy compression is that it reduces the file size considerably. Please note that with lossy compression, the image can not be restored to its original form due to the data loss. If it isn’t necessary to keep the image data, lossy compression can be very helpful to reduce file size and save storage space.
The second method of image compression is lossless compression. In this process, no image data is lost, but the data is arranged differently. The bytes are encoded into a more efficient coding. It preserves the quality but results in much larger files compared to lossy compression. The benefit of lossless compression is that the file can be restored in its original form.
Why compress your photos?
The amount of data stored on your website has an influence on the website speed. When compressing images, the file size is reduced and will take up less space. By reducing the size of images that are on your website, you also reduce the total data that needs to be loaded each time a viewer visits. Therefore compressed photos can make your page speed faster which is essential for the user’s attention.
Optimized images and SEO
Search Engine Optimization (SEO) is the process of improving your website to be more visible and relevant to user search queries in search engines. The better the SEO the higher you rank in the search engine. This is important because it will determine the amount of attention and visitors your website will get.
To improve the SEO, you have to optimize your website’s technical configuration, content relevance and link popularity. Reducing the file size of your images will help the technical configuration because it improves the website speed. So next to improving your website speed and the user experience of your website, image compression also helps to rank higher in search engines.
How to reduce image size?
There are different ways to reduce image size. First, you can save all your images in WebP, a format meant for web use that enables smaller file sizes with minimal quality loss. However, some people are reluctant to use WebP files since they are not supported yet by every browser. Another option to reduce the file size is to use an image compressor.
There are online image compressors available where you can upload your images, convert them to smaller file sizes and download them. This is one of the most easy-to-use methods because it doesn’t require any installation or setup. In addition, there are other options available to compress your images like plugins for your website, plugins for programs like Photoshop, APIs, and CDNs. Just to name a few options.
When selecting your image compression solution, there are many things that you can take into consideration, for example speed, uptime, data handling or maximum upload size. Keep in mind that each provider has their own unique compression algorithm. This means that the compressed results will vary in compression methods, quality and compression rates. Before picking your tool, it is recommended to optimize some test images and see if you are content with the results. If this triggers decision paralysis, you can for example start with finding a solution that fits your workflow. If you have a WordPress website, it will make sense to find a WordPress plugin that can automatically compress your images on upload.
In short, image compression is the act of reducing file-sizes of images through either a lossy or lossless method. However, like mentioned in this blog, image compression has many benefits that you don’t want to miss out on. If you are interested in how much space you can save by compressing your images and how much your website will gain from this, feel free to use the Tinify Analyzer tool.