We introduce PeriFast/Corrosion, a MATLAB code that uses the fast convolution-based method (FCBM) for peridynamic (PD) models of corrosion damage. The FCBM uses the convolutional structure of PD equations and employs the Fast Fourier transform (FFT) to achieve a computational complexity of ๐(๐๐๐๐๐ ). PeriFast/Corrosion has significantly lower memory allocation needs, ๐(๐), compared with, for example, the meshfree method with direct summation for PD models that requires ๐(๐ 2 ). The PD corrosion model and the fast convolution-based method are briefly reviewed and the detailed structure of the code is presented. The code efficiently solves 3D uniform corrosion (in copper) and pitting corrosion (in stainless steel) problems with multiple growing and merging pits, set in a complicated shape sample. Discussions on possible immediate extensions of the code to other corrosion damage problems are provided. PeriFast/Corrosion is a branch of PeriFast codes and is freely available on GitHub [1].