A method comprising: providing a graphical user interface element (320; 410; 1220) in a browser , wherein the browser provides multiple different identities (122, 126, 128; 1422) for the browser, the multiple different identities being associated with respective users, a first identity of the multiple different identities being associated with a plurality of respective accounts (123, 124, 125, 127, 129; 1424, 1426), a second identity of the multiple different identities being associated with one or more respective accounts; upon receiving a selection of the graphical user interface element from a first user, matching the first user with a first identity that is stored by the browser and associated with the first user; in response to the first user opening or accessing a web application associated with the browser: using the first identity to obtain a token , which was previously generated by the web application, when the first user previously visited the web application, and which is stored in association with the first identity and a first account of the first user; exposing the token to the web application, producing a short lived token or a short lived cookie by using the token , and authenticating the first user to the web application using the short lived token or the short lived cookie, wherein the token lives longer than the short lived token and the short lived cookie; syncing data associated with the first identity among multiple computing devices associated with the first identity, wherein the data comprises the token ; and upon receiving a second selection of the graphical user interface element from a second user, matching the second user with the second identity that is stored by the browser and associated with the second user. providing a graphical user interface element (320; 410; 1220) in a browser , wherein the browser provides multiple different identities (122, 126, 128; 1422) for the browser, the multiple different identities being associated with respective users, a first identity of the multiple different identities being associated with a plurality of respective accounts (123, 124, 125, 127, 129; 1424, 1426), a second identity of the multiple different identities being associated with one or more respective accounts; upon receiving a selection of the graphical user interface element from a first user, matching the first user with a first identity that is stored by the browser and associated with the first user; in response to the first user opening or accessing a web application associated with the browser: using the first identity to obtain a token , which was previously generated by the web application, when the first user previously visited the web application, and which is stored in association with the first identity and a first account of the first user; exposing the token to the web application, producing a short lived token or a short lived cookie by using the token , and authenticating the first user to the web application using the short lived token or the short lived cookie, wherein the token lives longer than the short lived token and the short lived cookie; syncing data associated with the first identity among multiple computing devices associated with the first identity, wherein the data comprises the token ; and upon receiving a second selection of the graphical user interface element from a second user, matching the second user with the second identity that is stored by the browser and associated with the second user. <EOS>