Do WebP manipulation supports transparent PNG formats in EE?

It does, but I think it might depend on your environment.

it works for me in ddev (locally) and in cloudways hosting.

do you mean our server?

Yes

But why can’t it run on our server? Thanks for confirming. I’ll try again.

I can’t remember what image library it relies on… but I’m sure that it’s like Imagick or something like that. Each host may have slightly different configurations for it.

try jcogs img

It might be a version issue with EE. It is not the first time this has come up, and I’m pretty sure that at some point in the recent-ish past EE’s image processing workflow had a defect (where it converted things to jpg before converting to wepb, losing transparency as a result, if I recall rightly); but I think that was fixed a while back.

But @Jelle / ee-websites.eu / Silver partner is right … for all sorts of very good reasons you should use JCOGS Image Pro for such conversions

🐾

There is a pr for a fix that might help. https://github.com/ExpressionEngine/ExpressionEngine/pull/5069