What size should the images be? It depends on the social media platform you are using. Here are some suggested sizes:
Twitter: 512px width x 1024px height
Facebook: 788px width x 940px height
Pinterest: 1102px width x 702px height
Instagram: 1080px x 1080px
In social media, the ideal size of an image may change over time. To keep up on these changes please visit here.
Make sure to optimize the size of your image file so it downloads quickly. To do that please reduce the image size and save it as a web file.
What format should your image be? For graphics, save an image as a png file. For photos, save them as jpegs.
Mark each photo with a description when you upload it to social media. Write a keyword phrase (description) in the “alt tag” so search engines can figure of what the image is about.
For more information about image sizes, please read here.