<p>Hydrogels have garnered significant attention due to their remarkable properties, including mechanical strength, electrical conductivity, controlled degradation, and thermal stability, which render them highly suitable for next-generation energy devices. Their flexibility, biocompatibility, and tunability facilitate applications in energy harvesting, sensing, and electronics. Innovations in nanocomposite and dual-network hydrogels have addressed challenges related to robustness and conductivity, while the integration of conductive polymers and nanomaterials has enhanced their performance in triboelectric nanogenerators, piezoelectric systems, and flexible transistors. This review highlights the synergy between the properties of hydrogel and their applications in energy technologies, including supercapacitors, batteries, sensors, actuators, and nanogenerators. It introduces emerging innovations such as hybrid hydrogel architectures and multifunctional composites, emphasizing their transformative role in energy solutions. The review also explores wearable and bio-integrated applications, including health-monitoring sensors and implantable energy sources. Key challenges, such as degradation control, sterility, and environmental resilience, are critically analyzed, and strategies to overcome these barriers are offered. This work bridges the gap between fundamental research and practical application, providing actionable insights for designing advanced hydrogels tailored to specific energy requirements.</p> Graphical abstract <p></p>