Here's a little neat trick that will save you so much time on finding reaction pics to use on 4chan.
>Go to a modern 4chan archive>Choose a board >Press "Stats" on the bar on top of the site>Choose "Image Reposts"And voila!
You can now have access over 100 reaction pics that can be downloaded, although some boards have broken images that can't be downloaded due to how dated they are and how haven't been reposted for a long time.
Here's the best place to get reaction pics:
https://arch.b4k.co/v/statistics/image-reposts/ 