This article reviews the use of hydrogels in flexible electronics and devices, highlighting their potential in various applications such as energy storage, touch panels, memristor devices, and sensors. Hydrogels, with their excellent flexibility, electrical conductivity, and tunable mechanical properties, are ideal conductive materials for flexible electronic devices. The review discusses the latest synthetic strategies for producing conductive and environmentally friendly hydrogels, as well as their applications in different fields. It also covers the fabrication techniques for sensors and the challenges and future research directions in the development of flexible and portable electronic devices based on hydrogels. The article emphasizes the importance of hydrogels in wearable and portable electronics, particularly in biosensors, energy harvesting devices, and smart actuators. The review concludes by discussing the unique properties of hydrogels, such as their ability to combine conductivity and mechanical properties, and their potential in various applications, including energy conversion, electronic skin, and health diagnosis.This article reviews the use of hydrogels in flexible electronics and devices, highlighting their potential in various applications such as energy storage, touch panels, memristor devices, and sensors. Hydrogels, with their excellent flexibility, electrical conductivity, and tunable mechanical properties, are ideal conductive materials for flexible electronic devices. The review discusses the latest synthetic strategies for producing conductive and environmentally friendly hydrogels, as well as their applications in different fields. It also covers the fabrication techniques for sensors and the challenges and future research directions in the development of flexible and portable electronic devices based on hydrogels. The article emphasizes the importance of hydrogels in wearable and portable electronics, particularly in biosensors, energy harvesting devices, and smart actuators. The review concludes by discussing the unique properties of hydrogels, such as their ability to combine conductivity and mechanical properties, and their potential in various applications, including energy conversion, electronic skin, and health diagnosis.