Apparently it's only possible if the search engine supports "open-search": https://community.brave.com/t/is-it-possible-to-add-a-new-search-engine-presearch/451

Apparently it's only possible if the search engine supports "open-search": https://community.brave.com/t/is-it-possible-to-add-a-new-search-engine-presearch/45196 https://community.brave.com/t/is-it-possible-to-add-a-new-se... None of the search engines that I want to use seem to support open-search, however. In Firefox this is not an issue and adding a custom search engine there is trivial.