DefenseFinder is a comprehensive resource designed to facilitate the exploration of antiphage defense mechanisms. Initially released in 2021, DefenseFinder has grown from 60 systems to 152 over the past three years. To address the increasing complexity and challenges in interpreting antiphage system detections, the authors have developed a hub of resources, including a web service, a knowledge base, and precomputed databases. The web service, DefenseFinder, has been updated to improve usability and add new features, such as a simple interface for depositing nucleic acid or amino acid sequences and dynamic tables for displaying results. The knowledge base, DefenseFinderWiki, provides detailed information on various defense systems, including descriptions, molecular mechanisms, genomic architecture, distribution, 3D structures, and experimental validation. Precomputed results of DefenseFinder on RefSeq complete genomes are available for visualizing and downloading. Additionally, a database of predicted 3D structures for known defense systems is provided, allowing users to visualize and download structures. The platform aims to support researchers, students, and enthusiasts in understanding and studying antiphage defense systems, fostering the use of bioinformatics in this field.DefenseFinder is a comprehensive resource designed to facilitate the exploration of antiphage defense mechanisms. Initially released in 2021, DefenseFinder has grown from 60 systems to 152 over the past three years. To address the increasing complexity and challenges in interpreting antiphage system detections, the authors have developed a hub of resources, including a web service, a knowledge base, and precomputed databases. The web service, DefenseFinder, has been updated to improve usability and add new features, such as a simple interface for depositing nucleic acid or amino acid sequences and dynamic tables for displaying results. The knowledge base, DefenseFinderWiki, provides detailed information on various defense systems, including descriptions, molecular mechanisms, genomic architecture, distribution, 3D structures, and experimental validation. Precomputed results of DefenseFinder on RefSeq complete genomes are available for visualizing and downloading. Additionally, a database of predicted 3D structures for known defense systems is provided, allowing users to visualize and download structures. The platform aims to support researchers, students, and enthusiasts in understanding and studying antiphage defense systems, fostering the use of bioinformatics in this field.