I came across this tip and found it very useful for photographers that needs to share images on Facebook.
Most people don't worry about artifacts in an image, but I know there are many out there, like me, who want to show their images in the best quality possible.
It only takes a couple of steps.
Basically, upload the image in PNG format, with a maximum width of 2048px
Hope this tips helps 😊
Here's the link to the article for all the fine details