A method, device, and system for browser-based application security verification is disclosed. A client device requests a browser-based application from a web server. An application security module of the client device intervenes and transmits an application verification request to a cloud service system. The cloud service system retrieves data regarding the security of the application and source from cloud resources and a local database of the cloud server. The cloud service system then uses the data to authenticate the source and verify the security of the browser-based application. The cloud service system provides the client device with a recommendation regarding the security of the browser-based application and updates its local database. The client device may then consider the recommendation in determining whether to download or execute the browser-based application and provide feedback to the cloud service system. The client device may also perform a local security analysis after receiving the cloud service system's recommendation.