Question

Is there a way to find out the number of objects stored in an S3 bucket

Answer 1

Frankly, that is not possible. This is what happens:

1. listing them all in batches of 1000 now this is very slow and consumes bandwidth
2. You may log into your account on S3, and go Account - Usage. It seems the billing dept knows exactly how many objects you have stored!

Now, downloading the list of all the objects will actually take some time and cost some money if you have 50 million objects stored.