Optimising website images is an essential part of modern website development and technical SEO strategy. It’s becoming increasingly clear that businesses and content creators want faster-loading sites and improved user experience. However many people are still questioning what is technical SEO? and how can I implement it into my website? This guide will show you how to optimise website images, using both general best practices and platform-specific tools to improve your website’s technical SEO.
Images are vital for engaging web content, however large, unoptimised images can slow down your website, negatively affecting:
Always upload images at the size they’ll be displayed:
For example:
You wouldn’t upload 3000×2000 pixels if your page only shows 800×600 pixels. Because the browser would automatically scale down the image to fit, but the image file still contains all of the data, and therefore would be slowing the page load.
When you optimise website images it’s important to remember smaller images load faster and reduce bandwidth usage.
Compression reduces file size while maintaining visual integrity. We exclusively recommend using WebP for your image formatting because:
| With Photoshop | With Squoosh.app |
| Open Photoshop.Open the image you want to edit.Make your edits.Go to File > Save a Copy.Choose WebP from the Format menu.Select Lossy or Lossless and adjust the Quality slider.Click Save / OK. | Go to squoosh.app in your browser. Click Upload and select your image. Open the dropdown under Compress on the right. Select WebP. Adjust the Quality slider to balance image clarity and file size. Click Download to save your WebP file. |
| Tip: This only works for versions of Photoshop 23.2 and newer. Anything older may require an additional plugin | Tip: Squoosh is free and works entirely in your browser, so it’s perfect for quick conversions without installing software. |
A responsive image is an image that changes size depending on the device it’s being viewed on. The goal is to make sure the image looks good but doesn’t waste data.
If your website always sends the biggest image, phones download more data than needed, slowing the page.
You can tell the browser in code to use srcset and sizes to serve different image sizes depending on device:
<img src="image-800.jpg"
srcset="image-400.jpg 400w, image-800.jpg 800w, image-1200.jpg 1200w"
sizes="(max-width: 600px) 400px, 800px"
alt="Optimised Sample Image">
Lazy loading simply means the website doesn’t load an image until it’s actually needed and it’s an important step to help optimise website images.
For example you open a web page with 10 images, lazy loading ensures the browser only downloads the images visible on your screen at that moment. The rest will download as you scroll down. This is how it looks in code:
<img src="image.jpg" loading="lazy" alt="Lazy Loaded Image">
This improves page speed, saves data and improves user experience because the page feels much quicker.
Alt text is a short description of an image that you include in your website’s code and can help optimise website images. Good alt text can:
Example: <img src="blue-shirt.jpg" alt="Blue cotton t-shirt on a hanger">
Optimising images isn’t one size-fits-all, different platforms have different tools and plugin options. Here is a simple guide:
ShortPixel – ShortPixel is a WordPress image optimiser. It has a free plan that gives you 100 credits per month to optimise batches of images. There are 2 paid options, either pay monthly or you can pay a one-off amount for lifetime access. We recommend lifetime deals where you can get them!
Smush – Smush is a popular plugin with a free plan that lets you bulk optimise website images, up to 50 images. The Pro version, from $6 per month, removes limits and adds WebP conversion, lazy loading, and a CDN.
EWWW Image Optimizer – Free for unlimited lossless compression. Paid plans ($7/month+) offer lossy compression, a CDN, and scheduled optimisation.
Imagify – Imagify’s free plan allows up to 20 MB of images per month. Paid plans from $4.99/month increase quotas and provide additional compression options. It’s very user-friendly for small and medium sites.
Optimole – Optimole automatically optimises images via a global CDN. Free for up to 5,000 monthly visits, paid plans start at $19/month. It also handles lazy loading and responsive image delivery.
Lazy Load by WP Rocket – Is a free plugin that improves page speed by lazy-loading images, videos, and iframes. It’s lightweight and easy to use, making it ideal for sites that want a simple speed boost.
TinyIMG – Free plan allows 50 image optimisations per month. Paid plans offer higher quotas. TinyIMG compresses images, converts to WebP, and provides SEO-friendly features like alt tags.
WebP Image Optimizer + Speed SEO – Free plan covers 100 images/month. Paid plans are one-off credit packs starting at $20. It combines WebP conversion, lazy loading, and SEO renaming.
AVADA SEO & Image Optimizer – Free for 50 images/month, paid at $34.95/month. It focuses on SEO-friendly compression and bulk optimisation for medium to large stores.
Crush.pics– Free plan allows 25 MB one-time optimisation. Paid plans from $4.99/month. It compresses images, automatically renames them, and optimises alt tags for SEO.
Built-in – Squarespace automatically resizes images and uses lazy loading. Most sites won’t need extra tools.
SQSkits Lazy Loading – A paid plugin that gives more control over how images load on scroll.
Website Speedy – Paid third-party service to improve page speed and optimise images with lazy loading, ideal for larger sites
Optimising website images isn’t just about smaller file sizes, it’s about faster websites, better user experiences, and improved search rankings. At Accentuate Agency, we specialise in making every image on your site work harder for you.
From converting files to WebP, implementing lazy loading, to selecting the right compression settings for your audience, we handle it all with precision.
Choosing a technical SEO agency, like ours, ensures you will save time, avoid costly trial and error and benefit from expert knowledge that ensures your site is fast, visually stunning and fully optimised for performance and SEO.
Absolutely. If you optimise website images, you will improve page speed, user experience and trust, which can directly increase sales and reduce cart abandonment.
Whenever you update your website or add new images you should re-optimise. Or if you implement new formats or compression tools, it’s a good idea to re-optimise to maintain speed and performance.
Ultimately, the best optimiser is one that reduces file size without compromising quality, is easy to integrate into your workflow and works well with your platform. For most users, a combination of automated platform tools and manual optimisation helps to cover all bases.
If you’d love to join our team, head to our careers page to find out more.
We actually post useful stuff 😬
Eleven Brindley Place
2 Brunswick Square
Birmingham
B1 2LP
© Accentuate Ltd 2025
