The utilization of antibody–drug conjugates (ADCs) represents a promising avenue for achieving precise drug delivery, thereby facilitating the targeted eradication of cancer cells while minimizing the adverse effects on healthy tissues. This approach seeks to ameliorate the side effects typically associated with conventional chemotherapy. Striking examples of ADCs include Kadcyla and Trodelvy, which have exhibited remarkable efficacy in the treatment of HER2-positive and triple-negative breast cancer (TNBC), respectively. Nonetheless, the complete realization of the clinical potential of ADCs faces substantial challenges. The prevailing ADC format exhibits a low drug-to-antibody ratio (DAR), necessitating the deployment of highly potent yet inherently toxic drugs, thereby increasing the risk of off-target toxicity. Additionally, stringent criteria regarding the stability and degradability of the antibody–drug linker introduce intricate design considerations and impose constraints on the selection of drugs compatible with ADC components. To address these challenges, we developed a versatile drug delivery platform known as antibody-nanogel conjugates (ANCs). This nanocarrier platform features (i) an easily functionalized surface for antibody decoration; (ii) simple preparation protocols; (iii) high drug loading capacity for a broad range of drugs thereby, significantly increases the DAR; (iv) low vehicle toxicity; and (v) triggerable on-demand release of cargo at targeted sites. The efficacy of our antibody-nanogel conjugate (ANC) systems was demonstrated through the fabrication of two ANCs containing identical cytotoxic payloads and targeting antibodies, analogous to Kadcyla and Trodelvy. in vitro assessments reveal a substantial increase in efficacy with the ANC system compared to the ADCs with several-folds improvement. Moreover, we have also presented a dual chemo-immunomodulator approach employing the ANC system. This strategy involves the conjugation of an anti-PD-L1 antibody to a nanogel encapsulating a chemotherapeutic agent. The aPDL1 antibody serves as an inhibitor for the PD-1/PD-L1 interaction, thereby activating the immune system's response against cancer cells. Concurrently, the chemotherapeutic drug exerts its effect by impeding cancer cell proliferation and promoting apoptosis in a synergistic fashion.