How do marketers conduct a website image audit?

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Published Aug 01, 2019 | Written by Jeremy Knight

Image optimisation can heavily influence the way search engines calculate your site rank, and, consequently, control how easy it is for searchers to find your site. Behind-the-scene elements such as page load time and keyword usage come to play here. If you want to be the number one search result for your product or service on Google or other SERPs, you really have to get a reign on your images.

In this post, we take a look at the benefits of a website image audit, and identify a handful of best practices.

What are you checking website images for?

There are a number of things for marketers to consider. The most common image optimisation issues are:

  • Accessibility guidelines
  • Image descriptions
  • File size
  • Broken, blurry or stretched images
  • Aesthetics - on brand? On point? In line with company values?
  • Mobile-first design

Images can be expensive to produce or curate. If you have invested time or money in procuring them, it makes sense to optimise them carefully to secure a higher ROI.

How to start

Performing a site-wide image audit is no mean feat, but the good news is that there are many online tools that can help.

First, you need an image checklist. If you’re not recording what has and hasn’t been checked, you may miss something important. In order to improve efficiency, you’ll want to set up a document where you can record progress as you go. This should look similar to a snag list. 

A list can be generated manually, but it is more time-efficient to use software. I suggest you use something simple like Screaming Frog.

Once you have an image list in place, you can begin your optimisation. SEMrush is able to point out easy wins like broken images, and missing alt tags - but for a more in-depth review, you may want to check out pingdom.

You should also have a keyword list handy, so that you can update your descriptions, file names and alt-tags with relevant, targeted language.

Read more about image optimisation


Do your images meet web accessibility guidelines?

For backgrounds, images that have text overlays, or fine line elements that convey real meaning (like icons or infographics) it’s important to make sure that there is sufficient colour contrast and readability. You can use tools like contrast checker to test this. WAVE: Website Accessibility Evaluation Tool, SortSite, aXe: The Accessibility Engine and tota11y also enable you to evaluate your images and report on accessibility.

Accurate image descriptions (file names, alt-tags and captions) are a contributing factor.

Improving the ease of use for all people who browse your website is essential best practice.

Image descriptions

As part of your SEO tactics, you should sweep your image descriptions for review. Missing alt text, ambiguous file names and a lack of captions can confuse users and pull you down the ranks on search engine result pages. On the other end of the spectrum, keyword stuffing can harm your results too. 

File size

Image file size has a big impact on page load time. So, it's important to optimise images for better site speed. Make sure you lower image byte size by removing unnecessary meta data, reducing the dpi, and resizing your image to no larger than the maximum required display.

Broken, blurry or stretched images

Are you linking to images that no longer exist in your file manager - or did you misspell a link? If images on a page cannot load it creates a frustrating experience for users and makes your website look poorly maintained. Weed them out and correct the issue. You can use SEMrush or other online visibility tools for this.

A blurry website image usually means that the image file you have uploaded is too small for the size it is being displayed at. For example, if your page is displaying a 100 x 100 pixel image at 500 x 500 pixels. It could also be blurry because the quality was reduced too harshly when it was saved for web.

A stretched image could be the result of human error during the editing process (forgetting to constrain proportions - meaning the source file is stretched) or using an image with the wrong aspect ratio for its display (meaning it is being stretched on page). 

Your native image size and dimensions should be as close to the on page display size and dimensions as possible.


The images you use speak volumes about your brand. 

Be wary of image sources, and the connotations surrounding any image you use. You don't want to cause hurt or offence by not considering image associations and the effect they will have on people's feelings. For example, if there has been a catastrophic world event, like a ship sinking, you may not want to post pictures that link to the Titanic. Whenever you post an image, remain sensitive to current affairs and the way your image might be interpreted.

You also need to consider the tone of voice an image portrays. If the tone is fun and vibrant, it can excite and engage. But this needs to be balanced against your topic. Is your image being used in a lighthearted, educational context, or in support of a more technical and serious topic? Somebody looking for a specific, functional piece of information may not be in the mood for your hijinks. 


business-image-audit (1)

Snuffles, you barely made the cut.

Think carefully about both the style and content of the images you use. Then think about the way your website images work together. Are they consistent, or is it a mishmash of looks? 

Mobile-first design

For many marketers, the concept of mobile-friendly design (and the desire to conquer it) is a driving factor for undergoing an image audit in the first place. More people than ever are searching on the go. Over 50% of worldwide web traffic was generated through mobile phones in 2018.

But data still takes longer to download on mobile than desktop. To keep a substantial portion of your audience happy, keep website image data streamlined so that it isn’t painfully slow to navigate your site on handheld devices.

Quick page load times improve your exposure in more ways than one. They lead to lower bounce rates and an improved user experience. It’s also something that is monitored and rewarded by search engines.


Review your website images with these goals in mind, and I'm sure you'll find a few that can be polished up. Image optimisation is an ongoing activity, and well worth the effort.

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Published by Jeremy Knight August 1, 2019
Jeremy Knight