Embodiments for anomaly detection on a web client are generally described herein. A processor on the web client is monitored, where a web browser is installed on the web client, with the web browser arranged to render a web page, the web page including content originating from a plurality of origins. A request from the web page to store data on the web client is intercepted, with the request originating from a particular origin of the plurality of origins. The request is analyzed and approved or denied based on the particular origin.