A method for collection instance resizing. The method may include identifying at least one collection object within a collection framework of a virtual machine. The method may also include determining the at least one identified collection object satisfies at least one preconfigured criteria. The method may further include determining a garbage collection cycle count associated with the at least one identified collection object exceeds a preconfigured threshold. The method may also include determining an occupancy ratio associated with the at least one identified collection object is less than a preconfigured shrink threshold. The method may further include restructuring the at least one identified collection object based on the at least one identified collection object satisfying the at least one preconfigured criteria, the garbage collection cycle count exceeding the preconfigured threshold, and the occupancy ratio being less than the preconfigured shrink threshold.