Best approach for generating API key

Question

So with lots of different services around now, Google APIs, Twitter API, Facebook API, etc etc.

Each service has an API key, like:

AIzaSyClzfrOzB818x55

Answer 1

I use UUIDs, formatted in lower case without dashes.

Generation is easy since most languages have it built in.

API keys can be compromised, in which case a user may want to cancel their API key and generate a new one, so your key generation method must be able to satisfy this requirement.