A user registering a new PubNub account is immediately granted free keys that have full access to the base API including all optional add-on features. As long as you stay within the limits of the Free Plan (1 million Transactions or Functions Executions), you can use it for as long as you need to. It is intended for testing and development purposes - once your application reaches production, you will need to upgrade to a paid account.
The Free Plan provides you with up to a million Transactions and it also includes Basic Support. Click here to get started today.