SEO image optimisation: what you need to do in 2026

Website load times are crucial, and you can improve them with image SEO. Here’s how:

Images can make or break your website’s performance. While they’re essential for making your site look good and feel engaging, if they’re not properly optimised, they can cause all kinds of problems. We all want to view, and to own, a fast-loading website. Here’s why optimising your images should be a priority:

1. Page Speed
Large, unoptimised images are one of the biggest culprits for slowing down your website. And let’s face it, nobody likes waiting for a site to load. Users will click away in seconds if your pages are sluggish.

Every second counts: A 1-second delay in page load time can lead to a 7% reduction in conversions.

By optimising your images, you can keep your site fast and responsive, giving users no reason to leave.

2. User Experience
Your website’s performance directly affects how people feel about it. A slow site leads to frustration, and frustrated users don’t stick around. Image optimisation improves load times, which means your visitors get a smoother, more enjoyable experience, and they’ll be more likely to engage with your content or services.

3. SEO
Optimising your images isn’t just good for overall user experience. It’s also crucial for SEO. When your images are correctly sized and formatted, they’re more likely to rank in Google’s image rankings, helping drive additional traffic to your site. Page speed is also a key ranking factor in Google’s algorithm. If your site is slow due to bloated images, it could hurt your organic search performance. Optimising your images ensures you stay on Google’s good side and avoid penalties for poor performance.

In short, image optimisation isn’t just a nice-to-have. It’s a must. It helps your site load faster, keeps visitors happy, and improves SEO. If your images aren’t working as hard as they could be, now’s the time to fix that.

SEO image optimisation techniques

Choose the right image file type

When you’re saving an image for your website, picking high-quality images of the right file type is essential. Each type has its strengths and weaknesses, and using the wrong one can impact your site’s performance or image quality. Here’s a quick guide to the most common file types:

JPEG
The go-to for most images on your site, JPEGs strike a great balance between quality and file size. They’re perfect for photos or detailed images where you want sharp visuals without slowing down your site. However, they’re not ideal for images with transparent backgrounds, logos, or line drawings. While some data may be lost during compression, the difference is rarely noticeable.

PNG
If your image has transparency, minimal colours, or a lot of text (like an infographic or logo), PNGs are the better choice. They deliver sharp, clean results, but the trade-off is larger file sizes, which can slow down your site if overused.

GIF
GIFs are handy for animations and can compress images into smaller file sizes. But they’re not ideal for photography due to their limited colour range. Use them sparingly for animated elements rather than static images.

TIFF
For maximum image quality, TIFFs are unmatched. They’re uncompressed, so there’s no loss of data, but they’re far too large for most websites. Reserve TIFFs for print projects or high-resolution files that won’t live online.

WebP
A newer image format that combines the best of both worlds: smaller file sizes and great quality. WebP is ideal for reducing your website’s load times without compromising visuals.

AVIF
AVIF is like WebP’s advanced cousin. It offers even better compression, meaning smaller file sizes with no drop in quality. If your website supports AVIF, it’s a fantastic choice for keeping things fast and efficient.

The bottom line: 99% of the time, you are choosing a JPG for your website images, a .png for the logo and a favicon, and you can upgrade this to WebP or AVIF via additional plugins. If you are on WordPress, I suggest TinyPng:

• Photos: Use JPEG for most photos, but keep an eye on file size.
• Graphics, Logos, and Icons: Go for PNG for sharp lines and clear text.
• Simple Animations: GIFs can add a fun touch, but use them sparingly.
• Prioritise speed: Explore WebP for superior compression, but ensure compatibility.

Resize and compress your images

Large images can drag your website’s speed down, big time. The frustrating part? It’s completely avoidable. Most websites don’t need images larger than their maximum display size, yet oversized files are one of the most common culprits of slow-loading pages.

And here’s the thing: most users won’t stick around for more than three seconds if your site doesn’t load. That’s why site speed isn’t just important. It’s critical.

The solution? Resize and compress your images. Resizing ensures your images fit within your site’s display limits, and compressing reduces the file size without sacrificing quality. Together, these steps can dramatically improve load times and keep your site running smoothly.

Step 1: what size should your images be?

Is your website built in WordPress? These are the sizes you need:

• Hero image max size: 1920 x 1200px (pixels)
• Images within the body of your website, square 800 x 800 px or rectangle 1200 x 800px.
• Images in your e-commerce shop: usually 800 x 800px

Need image sizes for Shopify? Shopify’s image size guide

For Squarespace: Squarespace’s guide to adding and resizing images

How to resize them

• Open Canva.com (or Adobe Photoshop if you are happier using that), choose Custom Size, and enter the size you want in pixels. Make sure you don’t get muddled between height and width. Make sure you download them in .jpg format, as my Canva at least always offers me .png first.
• If you work on an Apple Mac you can resize your images by double-clicking on the image to open it, clicking on Tools and then Adjust Size.
• Maintain aspect ratio: this fancy term refers to the proportional relationship between an image’s width and height. Resizing should maintain this ratio to avoid making your image look squished or stretched.
• Top tip: some website builder plugins automatically resize uploaded images. Try ShortPixel if your website is built in WordPress.

Remind me: why do I need to do this?

• Faster Loading Times: Smaller file sizes mean your website loads faster, keeping visitors happy and improving your SEO ranking.
• Improved Layout: Images that fit your website’s design create a balanced and visually pleasing experience for your website visitors.

Step 2: now it is time for image compression

Even after resizing, images can still be a bit bulky. We need to reduce the image file size. That’s where compression comes in. Compression techniques reduce the amount of data needed to store an image without sacrificing quality.

This is currently my favourite way to do this for free: compressimage.io

Drag the image(s) in from your desktop, press Download Zip once complete, and drag the download onto your desktop.

Even if you have only optimised 1 image, it will initially appear within what is called a .zip folder.

Double left-click on this .zip folder, which opens the folder and you will have the usual blue folder showing, probably named Untitled Design.

Open this folder (double left-click) and there’s your image!

Step 3: name your images

Google doesn’t ‘see’ your images.

This is why you need to name them correctly so that Google and any other search engines can ‘read’ the words within the name. Naming your images correctly, along with creating alt tags for every image, is super important for your search engine rankings.

Let’s pretend you have named your image image1234.jpg. Google will not be happy! It means nothing to Google.

If you are a service-based business, the image should be named: “main-keyword-location-if-relevant-your-business-name.jpg” If you have more than one image that is exactly the same, then the second one will be: “main-keyword-location-if-relevant-your-business-name-2.jpg” and so on.

If you have an eCommerce website, ie you have an online store, you may have any number of images of the same product, and I would suggest naming them such:

Imagine for a moment that your product is a mug decorated with yellow daffodils. You would name the images:

• yellow-daffodil-mug-front-business-name.jpg
• yellow-daffodil-mug-back-business-name.jpg
• yellow-daffodil-mug-top-business-name.jpg

I am sure you get the idea.

Step 4: upload your new images to your website

The easy bit!

One more action to go: adding your alt text. Alt text (alternative text) describes an image on a page. Alt text helps visually impaired people understand what the image shows, helps search engine bots understand image contents, and appears on a page when the image fails to load.

It is crucial to make your website accessible to all, and this is one of the vital steps to do so. However, the alt text should not be deliberately stuffed with keywords.

Step 5: add the alt text

Crafting well-written alt text works wonders for your SEO value. Even when pesky glitches prevent images from loading, search engines can still read the alternative text and utilise it to rank your page.

Furthermore, by adding appropriate alt tags to your website’s images, you can boost your chances of securing higher rankings in search engine results.

Most importantly, for those with visual impairments and who use screen readers, the reader will read your alt text description aloud.

Now, let me share some simple ground rules for your alt text:

Firstly, describe your images using plain and simple language, just as you did when naming your image files. No need for fancy jargon here.

Keep your alt text concise yet descriptive. Strike that perfect balance.

Lastly, let your creativity shine but resist the urge to stuff your alt attributes with excessive keywords. If one of your keywords would fit naturally into your description, then do use it, but don’t force them in for the sake of it.

For example, the alt text for a picture of Deborah Timperley’s glass sculpture could be A glass sculpture in the form of a wall in blues and greens by Deborah Timperley (note, no hyphens between words).

However, for a photo of a holiday villa, alt text of (and I am making this up) ‘Villa from Villa Holidays in Spain. Spain’s best-kept secret. Book with Villa Holidays’ is NOT appropriate.

It should read, ‘Villa with pool at night’ (but without quotation marks. Also note that there is no hyphen between words in alt text).

Image optimisation tools

Image optimisation plugin:

ShortPixel to compress your images and create WebP versions

Compressimage.io to compress the image only

Canva.com for resizing images

Testing your website’s speed performance

GTmetrix (you will need a free account, and set the test to the London server)

PageSpeed Insights

And don’t forget to audit the images already on your website

Just like you’d audit your site for technical SEO issues, it’s worth conducting an audit for the images already on your site. While you may be working hard to upload optimised images moving forward, pre-existing ones could still be holding your website back.

The goal of an image audit is to identify and fix issues that might be affecting your site’s performance. Key things to check include:

• Image sizes: Are any images unnecessarily large and slowing down your site?
• Image load speed: Are they taking too long to load?
• Alt text: Are any images missing descriptive alt text, which is crucial for both accessibility and SEO?
• Image format: Are your images saved in the most efficient file type for web use?

Don’t forget to look for broken image links as well. Nothing frustrates users more than a missing or unresponsive image.

To simplify the process, use tools like Screaming Frog to crawl your site. It can help you identify large files, missing alt text, and even generate an image inventory or sitemap. Taking the time to audit your existing images ensures your site looks and performs its best across desktop and mobile.

Step-by-step guide for image SEO: a reminder

1. Resize your image to the correct size for the website builder you are using (WordPress, Shopify, Squarespace, Wix and so on).
2. Download it as a .jpg. Remember, only logos and favicons are PNGs on websites!
3. Compress your image.
4. Rename the image.
5. Upload it to your website, pop it where you want it, and write your alt text.

You are done!

And check you are using the right image formats!

• Photos: Use JPEG for most photos, but keep an eye on file size.
• Graphics, Logos, and Icons: Go for PNG for sharp lines and clear text.
• Simple Animations: GIFs can add a fun touch, but use them sparingly.
• Prioritise speed: Explore WebP for superior compression, but ensure compatibility.

If you have worked through all of the above, congratulations! You are done.

Conclusion

If you are considering a new website and would like to be sure that you work with a web designer who understands the importance of SEO, my small business website design service is just what you are looking for. If your images are only one part of the problem, my SEO and AI search service covers the rest.