Best Practices
Initial Site Build
Here you can afford to be flexible in your use of less-efficient formats like JPEGs, if you want to, and then bulk-optimize pre-deployment.
Ideally, pre-optimize your images to AVIF or WEBP so that you can be certain of the fidelity level as you're building the site.
Ongoing Updates, e.g. Blog Posting
Unfortunately Webflow does not yet have an option to automatically optimize images as they're added to the CMS ( via Designer, Content Editor, or API ), which means that your client and content editors must be educated on how to prepare images properly.
Ideally, optimize your images before upload. This means teaching and tooling-up your editors. We like XnConvert.
Advanced Approaches
https://discourse.webflow.com/t/tools-for-optimising-images/68141
Automatic Optimization via Reverse Proxy
A reverse proxy can be constructed to identify and optimize all assets automatically, and also to specially prepare images for og:image as JPEGs so that they are broadly compatible with services like LinkedIn.
Systems for Automatic Optimization
Sygnal builds custom reverse proxy solutions that can automatically resize and WEBP all of the images on your site perfectly.
https://www.optily.co/
