I need a clickable image ....script

hey guys i like to know which is the best fitting size for facebook clickable images...

edited

I think anything 510px or over in width with height less than width works fine. I do 510 x 260 usually. If you're using wordpress you can install yoast seo plugin and set your image separate than the featured image. so it can meet the size requirements. I use it to add a fake play button to video posts.