Using webp across concrete5
From what I can tell, concrete itself doesn't recognise the .webp extension as an acceptable image format and it therefor doesn't allow me to use it without directly editing the theme.
Is there a way to add support for this format at all?
You are correct that concrete5 does not support WebP.
The easiest way to use it would be creating a custom image block that had a selector for a WebP image (selecting it as a file, not image) and a non-WebP fallback image. The image paths would then be used to create a picture element. This custom image block approach would offer basic support, but would not address image use in other core blocks and image functions.
The core could support it, but it would require generating and storing WebP versions of all images (cache images and thumbnails) and requiring different approaches to how it is displayed.
Simple way is to use the ‘content’ block.
First add ‘webp’ to allowed file types: Go to System & Settings/Allowed File Types and add ’webp’.
Convert your images/photos with an online converter then upload to the file manger (suggest you create a new folder called ‘Webp’).
Simply add the ‘content’ block and choose your image file from the ‘webp’ folder, add the dimensions, then ‘Add’ and ‘Publish’.