Very! Google Pay is actually safer than using a plastic credit card. Transactions using Google Pay are secure as Google keeps all payment information on secure servers. Your full card details are never stored on your phone or shared with merchants when you use Google Pay. Merchants are only provided with your Virtual Account Number.
When Google Pay is used for transactions a confirmation appears in the app which can assist you to detect suspicious activity sooner. This alert contains where the transaction occurred along with the merchant’s name and the amount of the payment or refund.
If you misplace your phone you can use Android Device Manager to either lock your device or perform a remote factory reset to prevent further Google Pay transactions being processed.