Speed
Optimising WordPress images for faster loading times
21 March 2025 · 5 min read
Images are the biggest culprit in slow WordPress websites. An unoptimised image of 5 MB can be reduced to 200 KB with the right techniques — without visible quality loss. That is a 96% reduction.
At WP Maintainer we optimise the images of all our clients monthly. In this article we share our proven approach.
Choose the right format
Compress before upload
The most important rule: compress images BEFORE uploading to WordPress. Useful tools: - **TinyPNG/TinyJPG** — online compression, free up to 20 files - **Squoosh** — Google's tool with side-by-side comparison - **ShortPixel** — WordPress plugin with bulk optimisation - **Imagify** — WordPress plugin with WebP conversion
Set the right dimensions
Do not upload images larger than necessary. An image displayed at 800px wide on the website does not need to be 4000px wide. Common sizes: - **Hero/header:** 1920×1080 px - **Content images:** 800-1200 px wide - **Thumbnails:** 300-400 px wide - **Logos:** 512×512 px (or SVG) - **Favicon:** 512×512 px
Implement lazy loading
Lazy loading only loads images when they come into view. This speeds up the initial page load considerably. Since WordPress 5.5, lazy loading is built in for images with the loading="lazy" attribute. For older versions or more advanced options there are plugins such as a3 Lazy Load or WP Rocket.
Use responsive images
WordPress automatically generates multiple sizes of each uploaded image. Make sure your theme uses the srcset attribute so the browser chooses the right size based on screen size.
Bulk optimisation of existing images
Do you already have hundreds of unoptimised images? No problem. Plugins such as ShortPixel, Imagify and Smush offer bulk optimisation. Note: make a backup first and test on a few images.
WP Maintainer service
Our maintenance plan includes monthly image optimisation. We convert to WebP, compress files, implement lazy loading and monitor performance. This keeps your website always fast, without you having to think about it.