Optimising featured images is essential to reduce the image file size without sacrificing quality. This improves your website’s performance by reducing page load times, enhances SEO rankings, and provides a better user experience. Optimised images also save hosting bandwidth and make your site more mobile-friendly.

The ideal size for a featured image varies depending on your theme, but common dimensions range from 1200×628 pixels to 1920×1080 pixels. It’s important to check your theme’s documentation for recommended image sizes to ensure the featured image displays properly without being cropped or distorted.

JPEG is the most widely used format for featured images due to its good quality-to-file-size ratio. PNG is ideal for images that require transparency or higher image quality but generally results in larger file sizes. For vector graphics or illustrations, SVG is a preferred format, though it may require an additional plugin for WordPress compatibility.

There are several tools to compress images without noticeable loss of quality, such as TinyPNG, JPEGmini, or ShortPixel. You can also install image optimisation plugins for WordPress, like Smush or Imagify, to automatically compress images during upload and reduce file size.

Yes, you can optimise existing featured images after uploading. Image optimisation plugins like Smush, Imagify, or EWWW Image Optimiser allow you to bulk compress previously uploaded images, improving load times and overall website performance.