In the rapidly evolving landscape of online marketing, businesses face a critical decision-making challenge in selecting the most suitable marketing channels. This study proposes a novel evaluation framework using the interval-valued neutrosophic TOPSIS (technique for order preference by similarity to ideal solution) approach to address this complex decision-making process. The interval-valued neutrosophic TOPSIS method offers a unique ability to handle uncertainties, vagueness, and indeterminacy in decision data, making it well-suited for the dynamic and multifaceted nature of online marketing channel selection. This research not only introduces the methodology but also provides a practical application of the proposed approach in the context of online marketing, highlighting its effectiveness in aiding decision-makers to make informed choices. By evaluating and choosing online marketing channels through the interval-valued neutrosophic TOPSIS approach, businesses can optimize their marketing strategies and improve their competitiveness in the digital era.