Query refinement in browser toolbar

Embodiments of the invention basically relate to extension of a tool bar of a web browser. The tool bar captures a search engine query of a user and recommends a refined search query which is known to be capable of generating better search results. The tool bar identifies that a webpage where the user is located is related to the search engine and acquires the search query of the user. The tool bar interacts with a refining assembly on a server. The refining assembly determines refined search query based on certainty factor scores distributed to data mined from data centers related to different search engines (the search engines related to tool bars). The refined search query is returned and displayed in a search box, so that the user can run the refined search on the different search engines easily.