Images can make or break a webpage. They’ll help grab attention, tell a story, and make your content more engaging, but if they’re not properly optimised, they can slow your site down and actually hurt your SEO.
The good news? A few small tweaks can make a big difference. And we’re here to help!
In this post, we’ll walk you through how to optimise your images for search engines without sacrificing quality, so your site loads faster, ranks better, and keeps users happy. A win-win.
The Importance of Optimising Your Images
When it comes to SEO, image optimisation often gets overlooked – but it really shouldn’t.
As well as making your site look good, optimising images makes it work better, too. Properly named files, well-written alt text, and the right image formats can actually boost your SEO, helping your content appear in image searches and improving your overall page rankings.
How to Optimise Images for SEO
Here are 5 steps for optimising your images for SEO:
1. Write Descriptive Alt Text
Alt text (short for “alternative text”) is a simple but powerful element in image SEO. It’s the text that describes an image when it can’t be displayed, and it’s also what screen readers use to describe images to users who are visually impaired.
From an SEO perspective, it gives search engines extra context about what’s shown in the image – since they can’t “see” images the way humans do.
When writing alt text, try to be clear and specific. Describe exactly what’s in the image, as if you were explaining it to someone who can’t see it.
It’s also worth noting that if the image is purely decorative (like a background pattern or a divider), it’s okay to leave the alt text empty, which tells screen readers to skip it, keeping the experience smooth for users relying on assistive tech.
2. Compress Large Images
One of the easiest and most effective ways to boost your site’s performance (and SEO) is to compress your images.
Uncompressed or oversized images over 100KB can seriously slow down your page load times, especially on mobile – and both users and search engines are quick to penalise slow sites.
Compression reduces the file size of your images without making them look bad. When done right, your images will still look crisp to users, but they’ll load much faster – improving both the user experience and your SEO rankings.
Tip: Use the 1200×800 ratio. This resolution is a sweet spot for web images – large enough to look sharp on most screens, but not so big that it drags down your site speed. Sticking to consistent dimensions also helps maintain a clean, cohesive look across your pages, which can improve overall design and usability.
3. Choose the Right File Format
Choosing the right image file format is just as important as compression when it comes to image optimisation. The format you use can affect both file size and visual quality, which directly impacts your site’s load speed, user experience, and SEO.
Different image formats serve different purposes. Picking the right one for each image ensures you’re not unnecessarily slowing down your site or sacrificing image quality.
The general rule of thumb is: use JPEG for photos (smaller file sizes, good quality), PNG for transparent images or graphics and WebP/AVIF for modern, highly compressed images (better performance)
4. Use Descriptive File Names
Files names matter more than most people think. Search engines like Google can’t “see” images – they rely on the surrounding content and the file name to understand what an image is about. That’s why using clear, descriptive file names is such a simple but powerful step in your optimisation process.
Instead of uploading something like IMG_1234.jpg or Screenshot1.png, rename the file to something that actually describes the image, like blue-running-shoes.jpg or vegan-chocolate-cake-recipe.jpg.
5. Use Non-Copyrighted Images
Using non-copyrighted images is crucial for both legal and SEO reasons. When you choose to use an image on your website, blog, or marketing materials, it’s essential to ensure you have the right to use that image.
Using copyrighted images without permission can lead to legal issues, penalties, or your content being taken down. But beyond the legal aspect, using properly licensed images also helps your SEO efforts in a couple of ways.
We recommend using platforms like Unsplash or Canva Pro.
How We Can Help
At Lumen SEO, we’re committed to helping businesses improve their search rankings and take their website’s user experience to the next level.
Whether it’s maintaining accessibility or optimising page speed, we can help you implement best practices that can boost user engagement and your search engine rankings.
Contact us today to get started.
