In conclusion, at the nanoscale, capillary force can generate high pressure, which is effective for the cold welding of metallic nanostructures. We have used a moisture-treatment to introduce capillarity for improving the performance of AgNW networks, including a remarkable increase in electrical conductance and mechanical stretchability, but negligible change in optical transmittance. The capillary-force-induced cold welding is also effective to recover damaged metal nanowire networks, and we have demonstrated that it is possible to recover damaged AgNW electrodes in a wearable electronic device in the outdoors by simply breathing water vapor on the AgNW electrode, without the use of any additional reagent or facility. This method may open a simple and convenient pathway for making high performance stretchable transparent electrodes, and can be used for the recovery of damaged metal-nanowire-based electrodes in outdoor wearable electronics. The capillary-force-based method may also be useful in the welding of other metal NWs, nanoscale interconnection, smart assemblies, and so forth.