The competitive advantage of small and medium enterprises (SMEs) has been identified as a key topic for scholars studying SME internationalization. Despite the fact that firm competitive advantage has long been discussed as a determinant of international performance, few studies have examined at the determinants of firm competitive advantage and their potential mediating role in the relationship between organizational capabilities and SMEs' international performance. As determinants of competitive advantage for exporting SMEs, there are four hypotheses of crucial export capabilities (market intelligence, product innovation, price, and marketing communications). The results of SEM with Smart PLS on a sample of 100 active exporting Indonesian SMEs show that three of these characteristics lead to competitive advantage. The main conclusion of this research will be useful for SMEs and startups who want to explore prospects in foreign markets.