A proxy server routes a request for online content from a user device to an origin server, which returns the requested online content to the proxy server. The proxy server passes the online content to the user device. In order to service subsequent user device requests with cached content, the proxy server, having received the initially requested online content from the origin server, parses out dynamic content specific to the user from static content common to many users within the web page content according to tags identifying the dynamic content. The proxy server stores the dynamic content within a personalized cache and also stores an association between the user/user device for the dynamic content stored. In this way, a subsequent request from the user device for the same online content may be serviced from cache, and include dynamic content specific to that user/user device by way of the personalized cache.