May 03, 2017 –

Why is optimising images important?

Author: Emma Yemm
Emma Yemm
Senior Digital Account Manager
Photo by: Ian Schneider
Optimising images is a vital component of successful website design. The benefits of doing so are manifold.

First and foremost, it helps website performance. Images need to be downloaded by a browser in order to display them, which can consequently put a strain on bandwidth. Ensuring images are optimised minimises this strain, helping to improve the website speed as less bytes require downloading. This means the browser is able to download content at a faster rate, rendering essential components (and therefore displaying the webpage to the user) more quickly.

But it’s not just website performance. Optimising images is an essential part of boosting a website’s SEO. While a heavy emphasis is put on including the right wording to improve search rankings, optimised images can play a large part.

Google (and indeed other search engines) is very clever in the methods with which it looks to organise rankings. Essentially Google is looking to provide the best search result for the user’s requirements. There’s no hidden motive there – it wants to be the best at what it does, offering the best service to encourage the most users.

As a website owner, you can do numerous things to assist Google’s algorithms in providing the right result and directly boost your page rank as a consequence.

Relevant Images

One important method is making sure that any images added to a website are relevant to the specific page or post they’re attached to. Not only does this improve the experience of the person visiting your website (everyone loves a picture after all), but when given the right file name, it will also add to the page’s SEO.

So, make sure to name it accordingly – if you’re writing a post about a specific subject and the image directly relates to that subject, be sure to use the subject in the file name. That way, Google will instantly know that the two are linked.

This is the same for text around the image. A relevant caption can help, although we wouldn’t advise using a caption for every image. Just use a caption when it fits, don’t try and force them in, otherwise it runs the risk of looking unnatural.

As mentioned, Google is intelligent, but it doesn’t mean you can’t assist it. Optimisation helps the search engines collate accurate information about the subject matter of your website and helps to improve SEO performance. By putting the right image alongside the relevant post, you’ll be helping to build a picture for Google’s algorithms.

Alt Text and Image Title

Alt Text is another important element to consider. This is a description of the image (contained within it) which appears when, for whatever reason, the image can’t be displayed to someone visiting the site. Image Title (different to image name) is text that appears when you hover your mouse cursor over the image.

Both of the above describe the content of the image and help those with poor vision and screen reader devices determine what the image is about, so be sure to use keywords to assist with this and make sure these contain them. Although not necessarily immediately obvious to the average page visitor, both Alt Text and Image Title play a part in the overall SEO picture established by Google.

Image format

Finally, choosing the best image format for your needs is also key. There are several formats used for website imagery, four of which are JPEG, GIF, PNG and SVG. All have differing merits, which make them suitable for different uses.

JPEG is the most commonly used thanks to the fact it keeps file sizes small, however lossy data compression means image quality can suffer, while it also fails to support transparent backgrounds.

GIF is used for simple art and animations, but isn’t great for photographs or photorealistic images due to its limited colour range. It does, however, support transparency so is particularly useful for displaying company logos and various page elements.

PNG supports transparency, has a better colour range, as well as automatic gamma correction ability.

SVG (scalable vector graphics) is a platform for two-dimensional graphics and is widely used in areas such as animation, web graphics, user interfaces, mobile applications, graphics interchange and high-quality design. It’s particularly common in high-spec graphical design such as that required in the automotive and aerospace industries.

To summarise then, the importance of optimising images shouldn’t be underestimated. Take the necessary steps as mentioned above and you’ll see immediate benefits, aiding both the user and helping Google, which, ultimately, enables you as the page owner to get better ROI on your website.

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