Loud Interactive emphasizes the importance of using modern image formats, as older formats such as BMP, JPEG, or PNG may not be as efficient in terms of size and quality.
Why is this important?
Contemporary image formats like JPEG 2000, JPEG XR, and WebP provide better compression and superior image quality, enabling significantly reduced file sizes.
What does the Optimization check?
This Optimization is activated by any internal URL that incorporates images in BMP, JPEG, or PNG formats that could benefit from being converted to WebP for optimization.
Loud Interactive audits the page, identifies BMP, JPEG, and PNG images, converts each to WebP, and triggers the Optimization if the potential savings exceed 8KiB.
How do you resolve this issue?
WebP is the go-to next-gen format backed by extensive browser support. You could potentially cut down image sizes by 25-50% when you switch to WebP.
To convert a large volume of images, consider the following:
Bulk WebP conversion tools
Node.js for automating conversion of images to WebP format.
CMS plugins, such as those for WordPress, to serve optimized WebP images.
It's essential to also provide JPEG/PNG alternatives for compatibility with browsers not supporting WebP.
Coordinate with your web developer to identify the most suitable conversion strategy for your website and resources.
Further Reading
Guidelines on implementing next-gen image formats (view Lighthouse documentation)
Tutorials on how to effectively use WebP images
Strategies for serving next-gen formats in WordPress environments