Large, unoptimised images are one of the most common causes of slow-loading websites. Optimising your images reduces file sizes without noticeably affecting quality, helping your site load faster and perform better in search engine rankings.
Best Practices for Image Optimisation
- Resize before uploading — Don't upload images straight from your camera or phone. Resize them to the maximum dimensions your website actually needs. For most websites, images wider than 1920px are unnecessary
- Use the right file format:
- JPEG — Best for photographs and images with lots of colour
- PNG — Best for graphics, logos, and images that need transparency
- WebP — A modern format that provides excellent compression. Most modern browsers support WebP
- Compress your images — Use a free tool like TinyPNG or ShortPixel to compress images before uploading them
- Use descriptive file names — Name your image files with relevant keywords (e.g. blue-mountain-hiking-trail.jpg) rather than generic names like IMG_1234.jpg. This helps with SEO
- Add alt text — Always add descriptive alt text to your images in WordPress. Alt text helps search engines understand your images and improves accessibility for visitors using screen readers
- Use lazy loading — WordPress enables lazy loading by default, which means images are only loaded as visitors scroll down the page. This helps speed up initial page load times
Using a Plugin for Automatic Optimisation
If you'd like to automate the process, consider installing a free image optimisation plugin such as:
- ShortPixel — Automatically compresses images as you upload them
- Imagify — Offers multiple compression levels to balance quality and file size
- Smush — Compresses and resizes images in bulk
These plugins can also optimise images you've already uploaded to your media library.