Yes, the online version of Quicken is secure. It uses bank-level encryption to protect user data and offers multi-factor authentication for added security. This means that users' financial data is protected both when it is being transmitted and when it is stored on Quicken's servers. Additionally, Quicken regularly undergoes security audits to ensure that its security protocols are up-to-date and effective. Overall, users can feel confident that their financial information is safe when using the online version of Quicken. However, as with any online service, it is still important for users to take basic security precautions, such as using strong passwords and avoiding public Wi-Fi networks.