Image Optimization and File Type


You might be wondering why image optimization and file type are important factors in the design of your website and you may be surprised to know that the major reason is linked to organic search engine rankings.


Absolutely. You see page speed is a massive factor in how your website is perceived by the search engines, both directly in that the search engines want fast responsive sites at the tip of their results, and indirectly in that they also look at bounce rate and nothing makes users bounce more than a slow loading page.

Does size matter?

It does! Whereas printing typically requires a minimum of 300 DPI high resolution in order to produce a quality image, all we need really is 72 DPI as this works from a screen resolution perspective as well as in terms of file size.

Generally when we receive images from clients they are around one to two Megabytes which is far too big; your entire page should be less than that. Really the largest any image should be is 200kb and ideally under 100kb; but we can help you with this.

File Type

Well, choosing the right file type really comes down to what you are using the image for; its purpose on the page. File types can be wide ranging but typically we work with jpg, gif, png or svg.


JPEGs tend to be used for out and out pictures like a photograph or digitally generated image. The JPEG can be compressed considerably and easily which makes it an attractive file type to use. It balanced image quality and file size nicely.


GIFs are used, in the main, for things like banner ads where you may want effects like a flicker or other type of movement. They are lower quality than a JPEG, but remain in use due to their ability to take animation.


PNGs are great for logo as you can set their image quality to not deteriorate with different resolutions. They are a popular alternative to GIFs too as they support a much wider colour palette and they don’t degrade over time as you save and re-save like a JPEG does. Where it falls down against the JPEG is in the file size department.


SVGs are best used for icons. They are often smaller in size than PNGs and thus load much quicker.


If you would like to find out more about file types, please don’t hesitate to get in touch via out contact page

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