<p>Electrochromic windows with full-spectrum solar radiation management offer an energy-efficient route to regulate daylight and solar heat gain, improving indoor comfort while reducing energy demand in buildings and vehicles. However, their conventional battery-like multilayer architectures often suffer from costly fabrication and performance degradation arising from complex interfacial reactions, making it challenging to achieve stable full-spectrum and deep-tinted modulation at an agreeable cost. Here we report an all-in-one electrochromic glazing based on an organogel containing suspended polyoxometalate clusters. Upon electrochemical bias, the clusters undergo multielectron transfer at the electrode interface, inducing intercluster aggregation that generates plasmon-augmented near-infrared absorption. As a result, the glazing achieves a deep-tinted state with a minimum transmittance of 1.4% and a high solar radiation modulation of 86.4%. Spatial confinement of clusters within the polar polymer matrix suppresses uncontrolled aggregate growth, allowing the device to retain 90.3% optical modulation at 600 nm after 50,000 cycles. The simplified architecture also enables scalable fabrication of large-area devices (&gt;900 cm²) that maintain stable solar radiation modulation over more than 10,000 cycles. Our findings outline a scalable strategy for solar-adaptive smart windows that support net-zero energy buildings and low-carbon transportation.</p>