A web browser can manage different session cookies associated with a website by storing the session cookies in distinct tab storage locations associated with different tabs of the web browser, instead of in a global storage location accessible by any tab of the web browser. When the web browser prepares to send a request associated with an active tab to a server associated with the website, the web browser can temporarily copy a corresponding session cookie into the global storage location from the tab storage location associated with the active tab. Accordingly, even if the website does not natively support multiple concurrent user sessions with the web browser, the web browser can send different session cookies to the website based on which tab of the web browser is active, and thereby allow users to engage in different user sessions with the website in different tabs.