Where to report a lost dog?

My family has recently found a stray dog. I took him to the vet’s office to see if he had a micro chip, and he does not. He is in good shape, has healthy teeth and gums, and is not neutered.

What is the best way to get the word out in the neighborhood that we have found him?

Are there websites for missing pets where I can upload some photos?

I don’t want to take him to the pound and am trying to do everything I can in case someone is missing him.

He knows basic commands and is calm and well behaved.

Your advice is greatly appreciated!