If my website has the speed optimizer plugin provided by siteground, is it necessary to download another image optimizer like smush?
If you have a lot of images then I would add another optimizer, otherwise the speed optimizer by SG is enough.
ok thanks! and is it ok that sometimes a banner pops up saying “you have to image optimizer plugins”?
shortpixel is another plugin for images.
where do you see this message?
its not showing now because i crossed it off but it was showing on the wordpress dashboard…
Another vote for Shortpixel 
And yes, it’s a good feature, it’s good that it’s not running image optimization when you have it from another plugin, and it’s not an issue.
ok thanks!