How to check if img is Webp?

[David]

Hi, A programmer is telling me a website is serving all the images in WebP format. But when I check the source code all the images are .jpg. Shouldn’t it be .webp ? Or is it possible it remains as .jpg while its served in WebP format? Furthermore the loaded images have a width and hight of 800px, while the showed thumbs are around 200px. The programmer tells me that’s o.k. because it’s WebP. But wouldn’t it be better for performance to use 200px images? Hope someone can tell me more. Thanks! – by /hq/IMconsultant – –