Abstract Wearable electronics have been attracting increasing attention because of the potential applications in health care and body motion monitoring. However, the existing wearable electronic devices often appear as an extra part of clothing and show limited compatibility with various textiles. Here, we report a general, low-cost, and easy operating approach to fabricate wearable sensors based on commercial or synthesized textiles, for which the textile itself is the active material for sensing, by loading with an ionic liquid on the fabric skeleton followed by depositing flexible electrodes. This is a general method that can activate many other daily used porous materials for sensing applications. Here, the textile or porous materials act as the elastic framework that allows for fast response (tens of milliseconds), whereas the ionic liquid plays the role of an active material to achieve high sensitivity (up to 10 kPa−1). The ionic liquid–activated wearable sensor allows for accurate monitoring of breathing, pulse wave, motion of the human joints, and plantar pressure. For clothing purpose, the sensor can be breathable, waterproof, washable, and antibacterial. This work provides a general strategy to make high-performance wearable electronics at low cost for health monitoring and motion detection.