Hubspot automatic image optimization

[jakubziemba]

Hi!

I have a question regarding the image optimization done by Hubspot. I've found some info in this link: https://developers.hubspot.com/docs/cms/developer-reference/cdn#image-compression-optimization-and-a..., especially this part: 

"We progressively enhance images to use the WebP format for browsers that support it. Images will be served WebP format images if the file size of that version of the image is smaller. This conversion happens server-side and does not change the file extension in the URL. An image uploaded as a .jpg, will still show as a .jpg in the URL but will be served as a WebP. This ensures links to this image will work for everyone regardless of WebP support."

While this sounds awesome, my question is: does Lighthouse / PageSpeed Insights "know" about it and does it affect the overall website score / health? 

Example: the image is uploaded in .jpg -> hubspot optimizes it and serves as .webp, but the URL still has .jpg file extension -> we still get "serve images in next-gen formats" -> does it affect our end score?

[amwilie · Accepted solution]

Lighthouse doesn't give the "Serve images in next-gen formats" message just because they're are pngs and jpgs on the page. They take those images, convert them to wepb, and then compare the file sizes. If the converted image results in a certain amount of data savings then it'll give the message. Since HubSpot is doing the conversion on the server side the file size Lighthouse will see is that of the converted image so when they do their size comparison it's not going to result in any savings thus yes, technically, Lighthouse "knows" about the conversion.

[jakubziemba]

this makes sense! thank you so much for the answer 🙏

[Jaycee_Lewis]

Thanks, @amwilie 🙌 You rock! — Jaycee