Settings – Replace method

This modifies how SPAI will replace the images with the optimized ones (remember that SPAI changes the URL of the image).

• SRC: this is the recommended method. It makes sure the images remain only with the src attribute, which resizes to the placeholder (“adaptive images”).
  • Generate <noscript> tag: If you are in a browser that does not allow/support JavaScript, then you should activate this in order to let SPAI work correctly. Please notice that this is not a “no-JavaScript” switch; this is a workaround, as SPAI works better if JavaScript is enabled.
• BOTH (experimental): it does the same as SRC, but it also keeps the srcset attribute while replacing images in it (but not resizing them).
• SRCSET (experimental): it only replaces images in the srcset attribute. Please notice that you do not need to select this to have “adaptive images”; SRC already serves adaptive images.

You should only choose BOTH or SRCSET if directed by support or if you are really sure you need them.