Restrict your API keys to be used by only the IP addresses, referrer URLs, and mobile apps that need them: By restricting the IP addresses, referrer URLs, and mobile apps that can use each key, you can reduce the impact of a compromised API key. You can specify the hosts and apps that can use each key from the console by opening the Credentials page and then either creating a new API key with the settings you want, or editing the settings of an API key.