Images are the most common cause of slow website loading on Mornington Peninsula business websites. A photographer uploads a raw image file at 6MB directly to their WordPress media library. A tradie’s “before and after” section includes uncompressed phone photos at 4MB each. A restaurant website loads twelve high-resolution food images, each straight from a DSLR, before a visitor has seen a single dish. In each case, the result is the same: a website that loads in five seconds or more on mobile — well above the two-second threshold that Google rewards and visitors tolerate.
Image optimisation is the process of reducing image file sizes without unacceptable loss of visual quality. Done correctly, it’s invisible to the visitor — the images look the same — but the performance impact is significant. A website that scored 45 on Google PageSpeed Insights mobile after fixing image issues alone can often reach 75 or above. We’ve seen a nutritionist client achieve a 28% traffic increase simply from speed optimisation — the content was already good, the site was just too slow to be rewarded for it.
The Three Dimensions of Image Optimisation
File size. The raw file size of the image — the number of kilobytes or megabytes the browser must download before displaying it. Smaller file sizes load faster. A photo that looks identical to the eye at 150KB and at 3MB has a load time difference of approximately two seconds on a typical 4G mobile connection — the difference between a visitor who stays and one who leaves.
File format. Different image formats achieve different file size vs quality trade-offs. JPEG is the traditional web format for photographs — good compression, widely supported. PNG is better for images with transparency or sharp edges (logos, diagrams). WebP is a modern format developed by Google that achieves approximately 30% smaller file sizes than JPEG at equivalent quality — and is now supported by all major browsers. AVIF achieves even better compression than WebP but has slightly less universal browser support. All new Click Websites builds use WebP as the default format, with JPEG fallback for older browsers.
Dimensions. An image displayed at 800 pixels wide on the page doesn’t need to be 4,000 pixels wide as a file. Uploading a 4,000px-wide image for an 800px display slot means the browser downloads four times more data than it needs to render the image correctly. Resizing images to the actual display dimensions before uploading — or using responsive image techniques that serve different sizes to different devices — eliminates this unnecessary data transfer.
Alt Text: SEO and Accessibility
Alt text is the text attribute added to an image tag that describes the image content. It serves two purposes: it tells screen readers what an image contains (making the website accessible to visually impaired users), and it provides additional keyword context to Google’s crawlers, which cannot “see” images the way humans do.
For a local business, alt text is a low-effort, high-impact on-page SEO element. An image of a completed bathroom renovation in Mount Eliza with alt text “bathroom renovation Mount Eliza — new tiles, vanity and fixtures” provides Google with location and service context that a generic alt text of “bathroom” doesn’t. This level of specificity across multiple images on a service page meaningfully reinforces its relevance for specific local search terms.
What to Do Right Now
Run your website through Google PageSpeed Insights (free at pagespeed.web.dev). If the “Opportunities” section shows “Serve images in next-gen formats” or “Properly size images” among the top recommendations, image optimisation is a priority improvement. WordPress plugins like Smush, ShortPixel, or Imagify automate the compression of existing and future uploaded images — one of the lowest-effort performance improvements available for an existing WordPress website.
Every website built by Click Websites is image-optimised from day one — WebP format, correctly sized, with descriptive alt text set. Our accountant client hits 95 on desktop and 90 on mobile — those scores don’t happen without rigorous image optimisation as part of the build process. Get in touch to discuss your website’s current performance, or review our pricing to understand what a properly optimised build involves.
Frequently Asked Questions
What’s the ideal maximum file size for website images?
For most web images, under 150KB is excellent; under 300KB is acceptable; over 500KB warrants optimisation. Hero images (large full-width images) can justify up to 300KB if the visual impact requires it. Background textures and small icons should be under 30KB. These are not rigid rules — the goal is the smallest file size that maintains acceptable visual quality at the actual display size on the page.
Does image optimisation help SEO directly?
Yes — through two mechanisms. First, faster loading pages score better in Google’s PageSpeed assessments, and page speed is a confirmed (though modest) ranking factor. Second, properly written alt text provides additional keyword context that contributes to page relevance signals. For a local business, alt text that includes specific service and location references across multiple images per page adds meaningful keyword density without keyword stuffing.
Should I use stock photos or original photography?
Original photography is strongly preferred — both for SEO and for conversion. Google’s E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness) framework rewards content that demonstrates first-hand experience. Original photos of your actual work, team, and premises signal genuine experience in a way that stock photos — which Google may recognise as not being original to your business — don’t. For a Peninsula business, original photos also provide local context that stock imagery structurally can’t.
What is lazy loading and should I use it?
Lazy loading is a technique that delays loading images that are below the visible portion of the page until the user scrolls toward them. This means images the visitor will never see (because they leave before scrolling that far) are never loaded — reducing both the data downloaded and the initial page load time. WordPress supports lazy loading natively for images added through the block editor. Enabling it is a standard performance recommendation for most websites.
How does image optimisation affect mobile users specifically?
Mobile users are disproportionately affected by large image files because mobile connections are typically slower and have lower bandwidth caps than fixed broadband. An image that loads in 0.5 seconds on desktop may take 3 seconds on a 4G mobile connection. Given that the majority of local business website visits happen on mobile — and that Google’s ranking algorithm now uses mobile performance as the primary standard — optimising for mobile image loading is the highest-leverage image optimisation priority.
Can I optimise images on my existing website myself?
Yes — for a WordPress website, plugins like Smush (free tier handles most cases), ShortPixel, or Imagify compress both existing media library images and new uploads automatically. The free tier of Smush will bulk compress your existing image library with no technical knowledge required. For manual optimisation, Squoosh (squoosh.app) is a free browser-based tool that compresses individual images with real-time quality preview — useful for large images that warrant specific attention before upload.
