The problem with screenshots is that they are NOT memes, and seldom ever fit the page you post them on. Please learn to do one of two things:
If you do not know the original source of a meme and cannot download the original for reposting, screenshot it and find the original using a google reverse image search. Sometimes, if your screenshot is crisp and shows the image well, you can crop it online for free using this App. Bookmark it or add it to your browser extensions. If you are using a mobile device, add a shortcut to it to your home screen.
https://picresize.com/

PicResize - Crop, Resize, Edit images online for free!
picresize.com

PicResize - Crop, Resize, Edit images online for free!

The original FREE picture resize and crop tool since 2005! Resize, crop, compress, add effects to your images, photos, and screenshots for free!