AbstractA smart glass, based on an eco‐friendly aqueous solution, capable of controlling both transparency for privacy and the radiant energy flow for thermal insulation, is demonstrated. The transparency of the glass is self‐adaptive in response to the ambient environment and can also be electrically controlled on demand. The aqueous solution used in this study is composed of water and a non‐ionic surfactant used in the food industry. As the temperature of the aqueous solutions increases above the cloud point, the solution undergoes phase separation into a micelle‐rich phase and a micelle‐poor phase causing the incident light to be scattered by the micellar clusters. Good thermo‐responsive optical properties are achieved with ≈77% luminous transmittance, ≈90% haze, and ≈64% solar regulation. The proposed smart glass fabricated from a biocompatible aqueous solution would be eco‐friendly as well as exhibiting excellent energy conservation performance.