We developed a web tool named ORTHOSCOPE to identify orthogroups of specific molecules within major bilaterian lineages. ORTHOSCOPE allows users to employ several sequences of a specific molecule and a user-specified species tree as queries. A test analysis using data from 36 bilaterians was accomplished within 140 seconds. ORTHOSCOPE is freely available at https://github.com/jun-inoue/orthoscope (last accessed August 5, 2018).