Why Image Compression Matters for SEO and Website Speed
Updated: 2025-10-09
Images are integral to modern web design. They illustrate products, enrich blog posts and convey emotions better than text alone. But large, unoptimised images are also one of the biggest culprits behind slow websites. When every kilobyte counts, compressing your photos can have a dramatic impact on loading times and search rankings.
Speed is a ranking factor
Search engines like Google increasingly emphasise performance metrics when determining where to rank pages. Bloated images increase the amount of data transferred over the network and delay when the page becomes interactive. Compressing pictures reduces this payload, leading to faster initial loads and smoother user experiences [1].
Better user engagement
Slow pages drive users away. Studies show that visitors abandon websites that take more than a few seconds to load. By reducing file sizes, you improve Core Web Vitals like Largest Contentful Paint and Interaction to Next Paint, resulting in lower bounce rates and higher engagement [2].
Lower hosting and bandwidth costs
If your site serves millions of images each month, even small optimisations add up. Cutting image file sizes by half can reduce your bandwidth bill by a similar proportion, saving money on data transfer and CDN fees [3].
Modern formats for even more savings
Traditional JPEG and PNG files are no longer the only options.
Next‑generation formats like WebP and AVIF can produce images that
are 25–35 % smaller than equivalent JPEGs while maintaining similar
quality
[4]. Many
browsers now support these formats, and you can use the
<picture> element to serve different encodings
based on the visitor’s capabilities.
Benefits of compressing your images
- Faster load times: Smaller images reduce network requests and improve perceived performance [1].
- Higher Core Web Vitals scores: Compressing images helps meet Google’s thresholds for Largest Contentful Paint and Total Blocking Time [2].
- Reduced bandwidth and costs: Smaller files mean lower hosting bills and faster transfer, which is especially important for mobile users and high‑traffic sites [3].
- Better caching efficiency: Reduced file sizes enable more assets to fit in browser caches, speeding repeat visits [1].
- Support for next‑gen formats: WebP and AVIF provide additional savings beyond what JPEG and PNG offer [4].
Conclusion
Compressing images is one of the most effective optimisations you can make. It boosts user engagement, improves SEO and reduces costs. With tools like SqueezeJPG, you can shrink your photos directly in your browser, preview quality changes, and download optimised files without sending anything to a server. Try compressing your images today and experience how much faster your website can be.