This paper is devoted to study the quantitative homogenization problems for nonlinear elliptic operators in perforated domains. In terms of L 2 -norm, we obtain O(ε 1/2 ) convergence rates on a C 1,1 region intersected a "regular" perforated domains. The extension arguments developed in [9, Theorem 2.1] and [29, Theorem 4.3] have been applied in a subtle way to weaken the regularity assumption on given data. In this regard, the result is new even for a linear model. Equipped with the error estimates, we may further develop an interior Lipschitz estimate at large scales, and the extension technique still plays a key role there.