Are facemasks effective ?

There is insufficient scientific research for a yes or no answer.
The effectiveness is still an argument.

"They are worn in hospitals, so they must work."
Masks come in various grades:
For medical purposes N95 grade is recognized as effective.
They are sold in medical outlets, and are priced accordingly.
Other masks sold are for dust protection only.
Generally sold in packs of three or more, masks are not individually coded.